ShouldProcess message and target need to be updated

When providing the `-WhatIf` to cmdlets, the message and target that come back aren't too meaningful to the user:

```
PS C:\> New-AzResourceGroup -Name generator-rg -Location centralus -WhatIf

What if: Performing the operation "New-AzResourceGroup_ResourceGroupNameLocationManagedByPropertiesTagsExpanded" on target "Call remote 'ResourceGroupsCreateOrUpdate' operation".

PS C:\> Remove-AzResourceGroup -Name generator-rg -WhatIf

What if: Performing the operation "Remove-AzResourceGroup_ResourceGroupNameEtcEtcEtcEtcEtcEtcEtcEtcEtc" on target "Call remote 'ResourceGroupsDelete' operation".
```

Ideally, the messages would be the following, respectively:

```
What if: Performing the operation "Creating new resource group 'generator-rg'" on target "Resource group 'generator-rg'".

What if: Performing the operation "Deleting resource group 'generator-rg'" on target "Resource group 'generator-rg'".
```

...or something to that nature. Something other than the variant name 😀