[native] Display the number of pinned messages in a banner across chat
Summary:
We want to display the number of pinned messages in a banner on top of chat the displays the number of pinned messages (if > 0 and if threadInfo contains a pinnedCount field since we gate it by hasMinCodeVersion on native).
The code is largely similar to on web: https://phab.comm.dev/D7310
Depends on D7608
Test Plan:
Check the banner to confirm the banner does not show if there are no pinned messages, and confirm that the banner appears for both 1 and more than 1 pinned messages.
Reviewers: atul, ginsu, tomek
Reviewed By: atul
Subscribers: ashoat
Differential Revision: https://phab.comm.dev/D7614