feat(webapp): chat component + button open search

Created by: Tirokk

🍰 Pullrequest

Issues

• fixes #6592 (closed)

Todo

• On click on the + button open search of user that has no rooms with self yet.
  • On select user open a room with the user
• set card title
• have a close button for the user search?
• change plus button to close button if open
  • not yet
• have not yourself and already opened rooms in selection?
• if one chose an existing room then select it in list?
• move components/Group/SelectUserSearch out of the folder?
• why id: 'search-user-to-add-to-group' comes as variable or prop?
• cleanup: search for Wolle