Add additional link to 2fa page

What does this MR do?

In this MR we add a 'leave group' link to the two-factor authentication page if a user was invited to a group that requires this - as it blocks the whole account. So this gives a user a choice.

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/53453

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