Resolve "User is unable revoke a Authorized application unless User OAuth applications is checked in admin settings"

What does this MR do?

Show oauth applications page even when User OAuth setting is disabled in the admin area. So users can see and revoke apps.

Screenshots

When User OAuth disabled you can only see and revoke apps:

When User OAuth enabled you can create apps too:

Old behavior:

When User OAuth disabled you can't access Applications tab and see apps you granted access to and revoke any of them.

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/47398

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides

Closes #47398 (closed)