Inconsistent IP address validation

**Describe the bug**
While the `--what-if` mode did not complain about invalid CIDR, deployment failed with the message: `IpSecurityRestriction.IpAddress is invalid. '123.123.123.123' is an invalid CIDR!`.

**To Reproduce**
Steps to reproduce the behavior:
1. run whatif mode with the following sample

```bicep
resource frontend 'Microsoft.Storage/storageAccounts@2022-05-01' = {
name: 'foo'
kind: 'StorageV2'
location:
sku: {
name: 'Standard_LRS'
}
properties: {
accessTier: 'Cool'
allowBlobPublicAccess: true
networkAcls: {
bypass: 'AzureServices'
ipRules: [
{
value: '123.123.123.123'
action: 'Allow'
}
]
defaultAction: 'Deny'
}
}
}

resource backendWebApp 'Microsoft.Web/sites@2022-03-01' = {
name: 'bar'
kind: 'app,linux'
location: location
identity: {
type: 'SystemAssigned'
}

properties: {
httpsOnly: true
serverFarmId: applicationServicePlan.id
clientAffinityEnabled: true
reserved: true
siteConfig: {
alwaysOn: true
http20Enabled: true
linuxFxVersion: 'PYTHON|3.10'
ipSecurityRestrictions: [
{
// documentation claims i can use a plain IP here, but that seems not to be the case.
ipAddress: '123.123.123.123'
action: 'Allow'
priority: 100
name: 'Some rule'
}
]
}
}
```
=> no error reported
2. Try the same as a real deployment => fails with `invalid CIDR`

**Expected behavior**
What if mode should report the same `invalid CIDR` error. Or alternatively, the deployment should autoconvert the plain IP Address into the desired format. Alternatively correct the documentation.

**Client** [e.g. PowerShell, CLI, API)
CLI

**Additional context**
- In the Azure UI I can provide "simple IP" addresses, they then get autoconverted to CIDR. Would be nice if this works here as well.
- That would also be more consistent with the ACL config for storage where plain IP addresses are also allowed

Start by reproducing the supplied Bicep sample in what-if mode and as a real deployment, focusing on the storage and web app IP validation paths. Confirm whether what-if should report the same invalid CIDR error; done means consistent behavior or corrected documentation for plain IP addresses.

Written by the indexing model from the issue text.