[keyserver] Mark ids in input validators

Summary:
We will also need to convert ids in the input, so this diff marks the ids for conversion inside existing input validators. tID should behave the same as t.String so there should be no runtime difference.

Depends on D7712

Test Plan:
Went through all existing input validators and sub-validators and changed t.String to tID in places where ids should be updated.
Test if the web and mobile app still work.

Reviewers: kamil, tomek

Reviewed By: tomek

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D7713