Refactor all 'get entity by primary key'-like queries not to use ORM

Summary: This differential refactors all get entity by string primary key queries not to use ORM.

Test Plan: Execute tests implemented in https://phab.comm.dev/D10711. get by string primary key queries are covered there.

Reviewers: kamil, michal

Reviewed By: kamil

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10705