Powershell changes for custom roles and bug fixes.

[shuagarw]

-Handle cases for roles with duplicate names and multiple assignments for a particular case.
-Authorization package version update to use get role definition by name filter.
-ProviderOperations version update to use a non preview version.
-Modify RoleDefinitionId to be displayed and taken Input just as a guid in role definition and assignment commands.
-Tests fixes, unskips and recordings.
-GetRoleDefinition command modification to take input either Name or Custom parameter, not both.
-Added RoleAssignmentId as a parameter in New and Remove RoleAssignment cmdlets.

[azurecla]

Hi @shuagarw, I'm your friendly neighborhood Azure Pull Request Bot (You can call me AZPRBOT). Thanks for your contribution!

It looks like you're working at Microsoft (shuagarw). If you're full-time, we DON'T require a contribution license agreement.

If you are a vendor, or work for Microsoft Open Technologies, DO please sign the electronic contribution license agreement. It will take 2 minutes and there's no faxing! https://cla.azure.com.

TTYL, AZPRBOT;