GW-011 Player Names

[IrenaRuprecht]

As a User
I want to enter my custom username when joining/hosting a game
so that others can see that name when they search for games and the host can see who is connected to the game.

Acceptance Criteria:

• Users can enter their custom username in the Multiplayer Screen.
• The host sees all usernames that are connected to the game.
• Joining players can see the hosts username.
• Joining players can select the hosts username and thereby join the game.