[native] introude thread avatar component

Summary:
After some discussion with @ashoat and @atul about how to fetch the ens avatars we decided to have two separate components to render avatars: UserAvatar and ThreadAvatar. This diff handles ThreadAvatar.

Generally, a thread avatar should not be able an ENS avatar since we won't be able to set it for threads; however, if the thread type is either PRIVATE or PERSONAL then if the user avatar type is ens then we need to render the ens user avatar

Depends on D7260

Test Plan:
I was able to render all three avatar types: Emoji, Image, and ENS:

Emoji:

Image by hardcoding: const avatarInfo = { type: 'image', uri: 'https://picsum.photos/200' }

ENS by hardcoding const avatarInfo = { type: 'ens' } and the other values like the provider and ethAddress from this gist

Reviewers: atul, ashoat

Reviewed By: ashoat

Subscribers: tomek, ashoat, atul

Differential Revision: https://phab.comm.dev/D7262