Changes to POST `/api/v0/main-frontend/credit-registration-admin/registrations/bulk-transition` - Moves a selection of rows by hand, one transaction for the lot. Resubmitting or cancelling refuses every row in `submission_uncertain`, whatever the selection said. Taking one of those back to `ready_to_submit` is a decision about one student's transcript, made after somebody has looked the attainment up; a checkbox in a list is not that, and a mis-click here would put a second attainment on every one of them. Those rows are reported back untouched, to be dealt with one at a time, as is a row whose earlier submission Suotar still holds open (`submission_pending`). Each attention item's `hand_actions` says in advance what this skips.

added the new already_cancelled enum value to the skipped/items/refusal response property for the response status 200

added the new awaiting_confirmation enum value to the skipped/items/refusal response property for the response status 200

added the new nothing_to_check enum value to the skipped/items/refusal response property for the response status 200

added the new still_in_pipeline enum value to the skipped/items/refusal response property for the response status 200

added the new submission_uncertain_too_recent enum value to the skipped/items/refusal response property for the response status 200

added the new already_submitted enum value to the skipped/items/refusal response property for the response status 200

added the new submission_pending enum value to the skipped/items/refusal response property for the response status 200

added the new required request property action

removed the required property skipped/items/reason from the response with the 200 status

removed the request property to_state

added the required property skipped/items/refusal to the response with the 200 status

endpoint added