Update export of role group members

[FabienTschanz]

Pull Request (PR) description

This PR updates the export format of the SCRoleGroupMember resource, where we now use the Alias property if it is an email address. Fallback to Name for every other type, like Service principals. This is to ensure uniqueness in a tenant, where multiple users with the same name can exist.

Due to the nature of this change (updating the name to its alias), this will result in drifts although the user itself didn't change, but our logic is not able to detect that without resolving the user. Therefore, I'll mark this as a breaking change.

This Pull Request (PR) fixes the following issues

• Fixes S&C Role Group member accepts only user DisplayName #6829

Task list

• Added an entry to the change log under the Unreleased section of the file CHANGELOG.md.
  Entry should say what was changed and how that affects users (if applicable), and
  reference the issue being resolved (if applicable).
• Resource parameter descriptions added/updated in the schema.mof.
• Resource documentation added/updated in README.md.
• Resource settings.json file contains all required permissions.
• Examples appropriately added/updated.
• Unit tests added/updated.
• New/changed code adheres to DSC Community Style Guidelines.