PLEASE NOTE THAT THIS DIFF AND SUBSEQUENT DIFFS IN THIS STACK WILL NOT BE LANDED UNTIL MORE OF THE REDESIGN IS READY SINCE THIS WILL CAUSE REGRESSIONS IN PROD
In D10719 I had to lift the logic for the send friend requests button to the AddUsersListModal component. To make things easier to review, I lifted part of the logic and created a few TODOs for me to circle back to (specifically with the logic for the pending users since that was going to have significant changes with the new checkbox ux)
This diff lifts the pendingUsersToAdd set to the AddUsersListModal component, and with pendingUsersToAdd now in AddUsersListModal I can fix up all the TODOs I set in D10719, and all the functionality should be working again
Linear task: https://linear.app/comm/issue/ENG-5957/update-the-ui-of-add-friends-modal
Depends on D10735