Add a Copy button to copy the team code

Right after creating a team, add a copy to clipboard icon next to the code so that it will make it easier for the users to share the code with their teammates.

Start at the view shown immediately after a team is created and locate where the team code is displayed. Add a copy-to-clipboard control beside the code, then verify that users can copy the code and share it with teammates.

Written by the indexing model from the issue text.