[web] Replace RainbowKit ConnectButton with ConnectedWalletInfo

Summary:
We kept ConnectButton around just to be able to check ConnectedWalletInfo against it, but now we can just remove since ConnectedWalletInfo is pretty much there. (Last thing is ENS avatars where it should be obvious if it's displayed or not)

Depends on D6635

Test Plan:
Looks as expected:

Reviewers: ashoat, tomek, ginsu, rohan

Reviewed By: ashoat

Differential Revision: https://phab.comm.dev/D6636