[web] Split EmojiAvatarSelectionModal into "Emoji" and "Color" tab
Summary:
Separate Emoji and Color into separate tabs.
NOTE: Layout/Styling will be handled separately.
WARNING: Took some liberties here with styling to unblock myself since emoji selection part of this modal wasn't part of designs (https://blob.sh/84e83d.png). Kept things as simple as possible, happy to iterate on this further. (cc @ashoat, @ted)
Depends on D8286
Test Plan:
Looks (and continues to work) as expected:
Reviewers: ashoat, ginsu, rohan
Reviewed By: ginsu
Subscribers: tomek, ashoat, ted
Differential Revision: https://phab.comm.dev/D8287