[Resource] Add new parameters to the What-If cmdlets to support excluding change types

[shenglol]

Description

• Added -ExcludeChangeTypes parameter to Get-AzDeploymentWhatIfResult and Get-AzResourceGroupDeploymentWhatIfResult
• Added -WhatIfExcludeChangeTypes parameter to New-AzDeployment and New-AzResourceGroupDeployment
• Updated Test-Az*Deployment cmdlets to show better error messages

This addresses Azure/arm-template-whatif#53.

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
  • the markdown help files have been regenerated using the commands listed here

[adxsdkps]

Can one of the admins verify this patch?

[VeryEarly]

please check comments,
is it possible to have test cases cover your code changes?

[shenglol]

please check comments,
is it possible to have test cases cover your code changes?

Yes. Added tests to cover the new parameter and the formatter.