WhatIf issues on Invoke-AzRestMethod

### Description

`Invoke-AzRestMethod` throws non-descriptive error when using `-WhatIf`

```Powershell
Invoke-AzRestMethod -Method "PATCH" -Uri "https://graph.microsoft.com/beta/groups/f686f775-adf2-4c11-902f-7f62449bdaf9" -Payload '{"description": "uli"}' -WhatIf
````

> Invoke-AzRestMethod: Object reference not set to an instance of an object.

----

CmdLet should give clear description if `-WhatIf` is not supported instead of throwing error by null access fault.

### Issue script & Debug output

```PowerShell
PS /home/janne> Invoke-AzRestMethod -Method "PATCH" -Uri "https://graph.microsoft.com/beta/groups/f686f775-adf2-4c11-902f-7f62449bdaf9" -Payload '{"description": "uli"}' -WhatIf
DEBUG: 4:37:52 PM - [ConfigManager] Got [True] from [DisplaySecretsWarning], Module = [], Cmdlet = [].
DEBUG: 4:37:52 PM - InvokeAzRestMethodCommand begin processing with ParameterSet 'ByURI'.
DEBUG: 4:37:52 PM - using account id 'MSI@50342'...
DEBUG: 4:37:52 PM - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: [Common.Authentication]: Authenticating using Account: 'MSI@50342', environment: 'AzureCloud', tenant: '0a8edbb9-667f-4120-88fd-2cd241f8236f'
DEBUG: 4:37:52 PM - [ConfigManager] Got nothing from [DisableInstanceDiscovery], Module = [], Cmdlet = []. Returning default value [False].
What if: Performing the operation "PATCH" on target "/beta/groups/f686f775-adf2-4c11-902f-7f62449bdaf9".
DEBUG: 4:37:52 PM - [ManagedServiceIdentityAuthenticator] Calling ManagedIdentityCredential.GetTokenAsync - TenantId:'0a8edbb9-667f-4120-88fd-2cd241f8236f', Scopes:'https://graph.microsoft.com/', UserId:''
DEBUG: ManagedIdentityCredential.GetToken invoked. Scopes: [ https://graph.microsoft.com/ ] ParentRequestId:
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] MSAL MSAL.CoreCLR with assembly version '4.61.3.0'. CorrelationId(9023656d-3085-4250-ba3f-ddcc1f077139)
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] === AcquireTokenForClientParameters ===
SendX5C: False
ForceRefresh: False

DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139]
=== Request Data ===
Authority Provided? - True
Scopes - https://graph.microsoft.com/
Extra Query Params Keys (space separated) -
ApiId - AcquireTokenForClient
IsConfidentialClient - True
SendX5C - False
LoginHint ? False
IsBrokerConfigured - False
HomeAccountId - False
CorrelationId - 9023656d-3085-4250-ba3f-ddcc1f077139
UserAssertion set: False
LongRunningOboCacheKey set: False
Region configured:

DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] === Token Acquisition (ClientCredentialRequest) started:
Scopes: https://graph.microsoft.com/
Authority Host: login.microsoftonline.com
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] [Region discovery] Not using a regional authority.
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] [Instance Discovery] Skipping Instance discovery because it is disabled.
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] [ClientCredentialRequest] Acquiring a token from the token provider.
DEBUG: Request [62614fb8-11d6-455f-b4a3-1eb7c2e9a48b] POST http://localhost:50342/oauth2/token
Content-Type:application/x-www-form-urlencoded
Metadata:REDACTED
x-ms-client-request-id:62614fb8-11d6-455f-b4a3-1eb7c2e9a48b
x-ms-return-client-request-id:true
User-Agent:azsdk-net-Identity/1.12.0 (.NET 8.0.8; CBL-Mariner/Linux)
client assembly: Azure.Identity
DEBUG: Response [62614fb8-11d6-455f-b4a3-1eb7c2e9a48b] 200 OK (00.0s)
X-Powered-By:REDACTED
ETag:W/"a18-TO2HnCHzIkVkXHCjFwSFuEWGoqk"
Date:Thu, 14 Nov 2024 16:37:52 GMT
Connection:keep-alive
Keep-Alive:REDACTED
Content-Type:application/json; charset=utf-8
Content-Length:2584

DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] Checking client info returned from the server..
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] Saving token response to cache..
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] [SaveTokenResponseAsync] ID Token not present in response.
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] Cannot determine home account ID - or id token or no client info and no subject
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] [SaveTokenResponseAsync] Saving AT in cache and removing overlapping ATs...
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] Looking for scopes for the authority in the cache which intersect with https://graph.microsoft.com/
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] Intersecting scope entries count - 0
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139]
=== Token Acquisition finished successfully:
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] AT expiration time: 11/14/2024 5:49:00 PM +00:00, scopes: https://graph.microsoft.com/. source: IdentityProvider
DEBUG: False MSAL 4.61.3.0 MSAL.CoreCLR .NET 8.0.8 Linux [2024-11-14 16:37:52Z - 9023656d-3085-4250-ba3f-ddcc1f077139] Fetched access token from host login.microsoftonline.com.
DEBUG: ManagedIdentityCredential.GetToken succeeded. Scopes: [ https://graph.microsoft.com/ ] ParentRequestId: ExpiresOn: 2024-11-14T17:49:00.4048823+00:00
DEBUG: [Common.Authentication]: Received token with LoginType 'User', Tenant: '0a8edbb9-667f-4120-88fd-2cd241f8236f', UserId: 'MSI@50342'
DEBUG: 4:37:52 PM - [ConfigManager] Got nothing from [EnableErrorRecordsPersistence], Module = [], Cmdlet = []. Returning default value [False].
Invoke-AzRestMethod: Object reference not set to an instance of an object.
DEBUG: 4:37:52 PM - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 4:37:52 PM - [ConfigManager] Got nothing from [DisplayRegionIdentified], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 4:37:52 PM - [ConfigManager] Got nothing from [CheckForUpgrade], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: AzureQoSEvent: Module: Az.Accounts:3.0.4; CommandName: Invoke-AzRestMethod; PSVersion: 7.4.5; IsSuccess: False; Duration: 00:00:00.1805695; SanitizeDuration: 00:00:00; Exception: Object reference not set to an instance of an object.;
DEBUG: 4:37:52 PM - [ConfigManager] Got [True] from [EnableDataCollection], Module = [], Cmdlet = [].
DEBUG: 4:37:52 PM - InvokeAzRestMethodCommand end processing.
```

### Environment data

```PowerShell
Name Value
---- -----
PSVersion 7.4.5
PSEdition Core
GitCommitId 7.4.5
OS CBL-Mariner/Linux
Platform Unix
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0
```

### Module versions

```PowerShell
ModuleType Version PreRelease Name ExportedCommands
---------- ------- ---------- ---- ----------------
Script 3.0.4 Az.Accounts {Add-AzEnvironment, Clear-AzConfig, Clear-AzContext, Clear-AzDef…
Script 8.4.0 Az.Compute {Add-AzImageDataDisk, Add-AzVhd, Add-AzVMAdditionalUnattendConte…
Script 7.9.0 Az.Network {Add-AzApplicationGatewayAuthenticationCertificate, Add-AzApplic…
Script 7.5.0 Az.Resources {Export-AzResourceGroup, Export-AzTemplateSpec, Get-AzDenyAssign…
Script 7.4.0 Az.Storage {Add-AzRmStorageContainerLegalHold, Add-AzStorageAccountManageme…
Script 1.1.3 Az.Tools.Predictor {Disable-AzPredictor, Enable-AzPredictor, Open-AzPredictorSurvey…
Script 0.0.0.10 AzureAD.Standard.Preview {Add-AzureADApplicationOwner, Add-AzureADDeviceRegisteredOwner, …
Script 0.9.3 AzurePSDrive
```

### Error output

```PowerShell
DEBUG: 4:39:03 PM - [ConfigManager] Got [True] from [DisplaySecretsWarning], Module = [], Cmdlet = [].
DEBUG: 4:39:03 PM - ResolveError begin processing with ParameterSet 'AnyErrorParameterSet'.
DEBUG: 4:39:03 PM - using account id 'MSI@50342'...
DEBUG: 4:39:03 PM - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 4:39:03 PM - [ConfigManager] Got [True] from [DisplaySecretsWarning], Module = [], Cmdlet = [].

HistoryId: 3

Message : Object reference not set to an instance of an object.
StackTrace : at Microsoft.Azure.Commands.Profile.Models.PSHttpResponse..ctor(AzureOperationResponse`1 response)
at Microsoft.Azure.Commands.Profile.Rest.InvokeAzRestMethodCommand.ExecuteCmdlet()
at
Microsoft.WindowsAzure.Commands.Utilities.Common.CmdletExtensions.<>c__3`1.b__3_0(T c)
at Microsoft.WindowsAzure.Commands.Utilities.Common.CmdletExtensions.ExecuteSynchronouslyOrAsJob[T](T cmdlet,
Action`1 executor)
at Microsoft.WindowsAzure.Commands.Utilities.Common.CmdletExtensions.ExecuteSynchronouslyOrAsJob[T](T cmdlet)
at Microsoft.WindowsAzure.Commands.Utilities.Common.AzurePSCmdlet.ProcessRecord()
Exception : System.NullReferenceException
InvocationInfo : {Invoke-AzRestMethod}
Line : Invoke-AzRestMethod -Method "PATCH" -Uri
"https://graph.microsoft.com/beta/groups/f686f775-adf2-4c11-902f-7f62449bdaf9" -Payload '{"description": "uli"}'
-WhatIf
Position : At line:1 char:1
+ Invoke-AzRestMethod -Method "PATCH" -Uri "https://graph.microsoft.com …
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HistoryId : 3

DEBUG: 4:39:03 PM - [ConfigManager] Got nothing from [DisplayRegionIdentified], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 4:39:03 PM - [ConfigManager] Got nothing from [CheckForUpgrade], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: AzureQoSEvent: Module: Az.Accounts:3.0.4; CommandName: Resolve-AzError; PSVersion: 7.4.5; IsSuccess: True; Duration: 00:00:00.0383525; SanitizeDuration: 00:00:00.0008848
DEBUG: 4:39:03 PM - [ConfigManager] Got [True] from [EnableDataCollection], Module = [], Cmdlet = [].
DEBUG: 4:39:03 PM - ResolveError end processing.
```