[native] extend emoji avatar creation to handle thread avatars

Summary:
Extend emoji avatar creation to handle thread avatars. I decided that the best way to handle this extension is to use threadID as a route param and if threadID (which is needed to save a thread avatar) is present then we should know that we are working with a thread avatar and not a user avatar

Depends on D7427

Test Plan:
Able to change both user avatars and thread avatars with the same expected user experience

Reviewers: ashoat, atul

Reviewed By: ashoat

Subscribers: ashoat, tomek, atul

Differential Revision: https://phab.comm.dev/D7428