[lib] client side logic for handling policy acknowledgment

Summary:
Adding a redux store in which will be stored data about user's policies, and action which will be dispatched on acknowledgment.

Context in ENG-2363.

There is a minor thing with this approach, there is possibility to dispatch the action multiple times, more in ENG-2431.

Test Plan: Connect to keyserver from account without accepted policies and check if action was properly dispatched after interaction with keyserver on both mobile/web.

Reviewers: tomek, atul

Reviewed By: tomek

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D5826