[CommCoreModule] add table for message store threads

Summary:
This code introduces new table for threads part of messages store. Skipping messageIDs as it can be computed based on message table.

start_reached will be represented as integer 1 and 0 (but will be sent as string from js code according to the current convention)

last_navigated_to and last_pruned are typed as BIGINT, SQLite`s concept of "type affinity" allows us to use INTEGER here but I believe BIGINT might make it clear to someone reading the code that this can not be stored in int. There are both approaches in the codebase so I chose the one I think is better

I think we will be querying based only on id so an additional index will not be needed.

Test Plan:
Tested migration for existing clients:

Tested creating a new database for fresh install:

Reviewers: tomek, marcin

Reviewed By: tomek

Subscribers: ashoat, atul

Differential Revision: https://phab.comm.dev/D7468