[keyserver] Check if we should create GENESIS

Summary:
Depending on the value returned from the function from the last diff, decide if we want to create GENESIS community.

https://linear.app/comm/issue/ENG-7843/use-the-variable-in-setup-dbjs-to-determine-if-we-should-create-the

Depends on D12226

Test Plan: Clear the DB. Run authoritative keyserver - the threads should be created. Run a non-auth keyserver - the threads shouldn't be created.

Reviewers: inka, ginsu

Reviewed By: inka

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D12227