[lib] Use tUserID in validators in keyserver/

Summary:
issue: ENG-7819
The approach I took is to go through all validators files in lib/types/validators and for each file, for each validator, recursively update all validators it uses

Then I went through all places where t.String was used and checked if they need to be updated - I think it makes sense to update all validators, not only ones used by output validators currently

Test Plan: flow

Reviewers: tomek, kamil, bartek

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11970