[native] added arrows for threads in chat inbox

Summary:
Implemented the arrows design for threads in chat inbox. Removed the icon, and moved the unread dot logic from chat-thread-list-item.react to chat-thread-list-sidebar

Next steps/diffs:

1. Include arrow design to be a part of SidebarListModal as well

won't land this diff until the next diff is also approved and ready to land

Linear Task: ENG-1779

Depends on D5253 and D5264

Test Plan:
Please view the video and the Figma designs attached to review the visual changes I made

Before:

After:

Figma:
Normal State
Swipe State

Reviewers: atul, abosh, rohan

Reviewed By: atul

Subscribers: ashoat, tomek, atul, abosh

Differential Revision: https://phab.comm.dev/D5268