TeamsGroupPolicyAssignment: Skip assignments that have orphaned/deleted groups or without display name

[ricmestre]

Pull Request (PR) description

If an assignment has a group that has been deleted, and/or orphaned, then skip it instead of throwing an error otherwise all assignments won't be saved into the blueprint even for the ones that were successfully exported up until the error occurred.

This Pull Request (PR) fixes the following issues

• Fixes TeamsGroupPolicyAssignment: Export stops if it finds an assignment with an orphaned/deleted group #4407

[NikCharlebois]

We recently ran into a similar issue with AADConditionalAccessPolicy, where we were simply skipping invalid groups instead of throwing an error. The customer made a typo in the groups name, which resulted in the group being skipped and the policy got updated with 0 group in the ExcludedGroup policy which locked them out of their system. I believe we should use it as a rule of thumb to always error out when an invalid User or Group is specified as a value. Thoughts?

[ricmestre]

@NikCharlebois My understanding was that whenever such issues happened it needed to be solved in the customer's tenant rather then at the code level, but @malauter raised PR #4408 to solve a similar issue and we discussed about it, that's why I actually raised this PR.

But regardless we really need to reach a consensus on this topic so this doubt doesn't come up again.

EDIT: Just FYI, in my case because of one bogus Teams group assignment none of the assignments were actually exported and I can't export them for the customer until they solve this issue with their MS support.

[NikCharlebois]

After much thinking on this topic, the consensus should be that if an invalid group is specified, that the Set-targetResource should always throw the error, because otherwise it risks bringing the environment in an invalid state. From an Export perspective, it is fine to skip over those in my opinion. I will merge the PR.