When users on desktop sign-out of their content-area account, Sync enters a paused state that is triggered by an sign-in auth error. 

We should implement a proper solution and stop sync, instead. Namely:
 - After sign-out, state of ProfileSyncService should be clear about sync being stopped. The service should stop all data types. As a result, each data type can react to the situation accordingly (for instance, WALLET_DATA needs to get wiped when sync is not active).
 - After sign-in, sync should start again and reconfigure all data types. Thus, each data type perform its standard start-up procedure (for instance, WALLET_DATA can fetch all its data again).