API: Use Issues and MRs IID instead ID for project scope API query
In order to stay consistent with the web interface, we're planning to use Issues and MRs :iid
instead :id
for /projects/:id/issues/:id
and /projects/:id/merge_requests/:id
endpoints (and endpoints under these like /projects/:id/merge_requests/:id/merge
).
Further discussion can be found on #21699 (closed)
Important
This change should not affect V3 API.