Context: #5759 (comment)

We have a validator function called isValidGuidArray which currently outputs a boolean whether an array of GUIDs is valid or invalid. When a user specifies let's say 20 GUIDs, it's hard for the user to see which GUID caused the validation to fail.
Therefore, just like isValidUserPrincipalNameArray, we should output which value is not valid and return this to the user.

This means that all commands that use the isValidGuidArray function must be updated as well to throw a more precise error message.