Enable Cmdlet to manage AzADApplicationOwner via New-AzADServicePrincipal

When moving from AzureAD to Az.Resources module I had to comment out the following code and it currently has no replacement.

I am able to create a new service principal `new-azadserviceprincipal` however I am unable to add owners, other than the person who originally creates the SP and Managed Application.

```powershell
# #region Add extra owners on the Service principal
# Connect-AzureAD -TenantId $Tenant
# foreach ($admin in $SPAdmins)
# {
# $adminID = Get-AzADUser -UserPrincipalName $admin
# if ($adminID.Id)
# {
# try
# {
# Add-AzureADServicePrincipalOwner -ObjectId $sp.id -RefObjectId $adminID.Id -ErrorAction Stop -InformationAction Continue
# Add-AzureADApplicationOwner -ObjectId $appID.ObjectId -RefObjectId $adminid.Id -ErrorAction SilentlyContinue -InformationAction Continue
# }
# catch
# {
# Write-Warning $_.Exception.Message
# }
# }
# else
# {
# Write-Warning "AzADUser [$admin] not found!!!"
# }
# }
# #endregion
```

The Cmdlets are:
- Add-AzureADServicePrincipalOwner
- Add-AzureADApplicationOwner