[lib] Add reducer and action to store established holder

Summary:
First action from ENG-9285. Addresses ENG-9286.

Added reducer for holders and action to store already-established holder in the store.
We use it in the blob service upload hook, to store the initial holder, which previously was forgotten

Inspired by D12949

Depends on D13401, D13402

Test Plan:

• Reducer unit test
• Uploaded multimedia to a DM thread and used Redux Devtools to ensure the action was performed correctly

Reviewers: kamil, tomek

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D13403