ENG-4959
Depends on D9255

Adding threadHashes to threadStore, and updating it in thread-store-ops.js. More explanation of the approach in the previous diff.

Load the web app, check if hashes are in the threadStore.
Load the native app, check that:

• on first load the transform does not run (nothing persisted), migration runs and fills in the hashes
• when redux state is saved it is saved with threadHashes
• on subsequent loads, the threadHashes are correctly rehydrated