Move most of repository routes under - scope

What does this MR do?

Moves most of repository routes under - scope. For #29572 (closed).

Main thing here is in config/routes/repository.rb. All other changes are to make thiugs work as before

This will get us closer to putting all repository routes under - scope and simplify routing regex. Also it will let us get rid of some reserved words on project level after 13.0

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers