Use error message from backend when updating member role

Peter Hegmanrequested to merge
496741-updating-role-fails-with-could-not-update-role-if-email-not-in-restricted-domain into master

What does this MR do and why?

Related to #496741 (closed)

Since !154196 (merged) we no longer display the error message from the API response when updating a member's role. This can be confusing to users because they just get a generic message. This MR fixes this bug.

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Screenshots or screen recordings

Before After
Screenshot_2024-10-03_at_12.48.22_PM Screenshot_2024-10-03_at_12.45.27_PM

How to set up and validate locally

  1. Follow instructions in https://docs.gitlab.com/ee/development/ee_features.html#simulate-a-saas-instance to create a group with Premium or higher license
  2. Go to that group -> Members
  3. Add some members
  4. Go to that group -> Settings -> General -> Permissions and group features.
  5. Add an email to Restrict membership by email domain field
  6. Go to that group -> Members
  7. Click on a members role to open the drawer
  8. Try to change the role
Edited by Peter Hegman

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