[lib] Handle processing of the ops

Summary:
We're processing the actions one by one and report successful processing after it is done.

https://linear.app/comm/issue/ENG-7098/create-a-handler-that-processes-the-ops

Depends on D11366

Test Plan: Added a sleep to the handler after calling processDBStoreOperations and observed in Redux debugger that the ops were processed.

Reviewers: kamil, inka, will

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D11367