SCSecutityFilter should accept empty region as it's not mandatory

[pkernevez]

Description of the issue

SCSecutityFilter should accept empty region as it's not mandatory

Microsoft 365 DSC Version

1.23.1025.1

Which workloads are affected

Security & Compliance Center

The DSC configuration

1. Create a SCSecurityFilter with an empty region
2. Export it 
3. Apply the current configuration as Test-TargetResource doesn't accept an empty region

Verbose logs showing the problem

InvalidOperation: PowerShell DSC resource MSFT_SCSecurityFilter  failed to execute Test-TargetResource functionality with error message: Cannot validate argument on parameter 'Region'. The argument "" does not belong to the set "APC,AUS,CAN,EUR,FRA,GBR,IND,JPN,LAM,NAM" specified by the ValidateSet attribute. Supply an argument that is in the set and then try the command again.
CimException: The SendConfigurationApply function did not succeed.

Environment Information + PowerShell Version

No response