[web] use AddUsersList in SubchannelMembers

Summary:
This diff updates the SubchannelMembers to use the new AddUsersList that the add friends + add members modals uses. When I first initially attempted to implement this, I was running into an issue where the users in this list were not a part of the parent channel and instead I was seeing other users not apart of the parent channel or community

This was caused because I was initially using useAddMembersListUserInfos which has different logic for selecting members than what I needed for when you create a potential sub channel. To fix this I created a new hook called useSubchannelAddMembersListUserInfos which uses the logic previously found in SubchannelMembers for selecting the correct potential users and transformed that data to what was needed for the AddUsersList component

Linear task: https://linear.app/comm/issue/ENG-6735/add-member-list-for-subchannel-creation-is-not-reflecting-the-correct

Depends on D10994

Test Plan:
Please see the demo video below

Reviewers: atul, inka

Reviewed By: atul

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D11065