In this diff, we modify the @ mentioning tooltip for users to display resolved ENS names and also to allow users to type out ENS names and still get a match. For example, for a user `imbatman.eth`, if I type @ followed by '0x', I should see `imbatman.eth`. I should also be able to see this if I type '@im' now.
Because of these changes, we're able to remove unused code in `user-selectors`.
Depends on D10386
Addresses https://linear.app/comm/issue/ENG-5073/update-client-to-detect-ens-names-for-wallet-addresses