Update backend messages displayed for group migration failures

Problem description

This is a follow-up from #300684 (comment 513391345)

When a group migration fails on the backend, a message is propagated to the frontend and displayed to the user.

image

The message reads Validation failed: Destination namespace destination group cannot be part of the source group tree. This message does not convey the fact that the migration failed. It also does not provide the user with a suggestion on how to proceed.

There may be additional backend messages, which may need review and a potential update.

Updating the user experience (red banner) is considered in a separate frontend issue.

Proposed solution

Update the message as follows:

  • Old message: Validation failed: Destination namespace destination group cannot be part of the source group tree
  • New message: Import failed: Destination cannot be a subgroup of the source group. Change the destination group and try again.

To do

  • List all the messages
  • Propose a better copy

Documentation

The following documentation may need to be updated:

Edited by Haris Delalić