Refactor of ConnectionRepository calls and usages in the project.

[carlosarismendi]

• Moved repository calls from use cases to controllers in most actions (missing create/join room actions).
• Added wsrouter.Context.Bind(...) method so controllers can use it to unmarshall input parameters. This way a wrapper can be added to the error.
• Changed *shared.WsConn to be domain.ConnectionRepository in domain.Player. Removed ConnectionRepository attributes in wsrouter.Context.