Enable SQLite database to hold two olm accounts: content and notifs

Summary: This differential enables SQLite database to hold to olm accounts: content and notifs.

Test Plan: Run olm tables tests from database/queries directory.

Reviewers: kamil, michal

Reviewed By: kamil, michal

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D11127