Allow user to edit nickname

[kingdomlevel]

New functionality (possibly component?) in LobbyContainer.

• creation of an edit button next to 'this' client's pre-generated nickname. clicking this will...
• create a text input pre-populated with nickname to edit nickname and a button to confirm
• on confirm, pass this back up to RoomContainer where 'this' client's nickname is held
• write a new method in socket-helper to inform server that nickname has been updated
• server accesses client in allRooms['${gameCode}'].players['${socketId'}]` and updates their nickname prop
• server emits this info to all clients in room except sender

depends on #11