[keyserver] Convert websocket input

Summary:
Changes the websocket validation logic to convert the ids (after enabling the flag).

Depends D7749

Test Plan:
Check if any of the input validators needed to be updated to mark the IDs (they were all using validators which have been marked in previous diffs).
Check if web and ios app work fine, and there aren't any errors.

Reviewers: kamil, tomek

Reviewed By: tomek

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D7750