Adjust applied suggestion reverting previous changes

What does this MR do?

1. Avoid suggestions being applied on the same file from reverting previous changes (major bug)
2. Gracefully use and handle Files::UpdateService::FileChangedError when updating the file by passing the latest_commit_sha to the Files::UpdateService. It does not fully solves the sync problem of multiple file update requests coming at once. This requires further discussion and will be handled in a separate MR.

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56017

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer