Check HTTP methods in Cop/Put{Project,Group}RoutesUnderScope

What does this MR do?

Previously, Cop/PutProjectRoutesUnderScope and Cop/PutGroupRoutesUnderScope were only checking resource and resources and skipped checking trivial routes like get, post etc.

This commit unifies both cops and adds the ability to check HTTP methods.

Why?

We were adding new trivial routes (get, post ...) which were not scoped under /-/. We should warn devs and reviewers.

This came during a post-review (#230459 (comment 382243282)) while working on !37314 (merged).

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
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team