Fix grape-route-helper route shadowing

What does this MR do?

Fixes a bug on grape-route-helpers gem in which a route with less arguments can shadow another route with more arguments but the same name (example: api_v4_projects_merge_requests_path(id: 1, merge_request_iid: 2) and api_v4_projects_merge_requests_path(id: 3))

Are there points in the code the reviewer needs to double check?

The tests I added depend on existing API routes and so run the risk of breaking if these routes are changed

Why was this MR needed?

I attempted to fix this bug upstream but the project is abandoned. Since it's only a one-line fix I opted to monkey-patch the fix directly inside the pre-existing grape_route_helpers_fix.rb file.

This bug can be surprising when using grape-route-helpers as you would expect a route with the same name but more params than another to work. Instead though the route ends up shadowed and requires the developer to set a different name explicitly in order to be able to access it.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?