Resolve "Block emojis and symbol characters from user's full names"

What does this MR do?

This MR adds inline validation to the user settings page to prevent users from adding emojis to their full name.

In addition it fixes a bunch of tests in spec/features/profiles/user_edit_profile_spec.rb that were failing locally due to timeout issues.

emoji_validation

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/50521

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• 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

Closes #50521 (closed)