Support aliases (user defined display names) for Snapclients

[zwometer]

A snapcast client is shown with the standard device name that is not always easily readable. A solution would be the support of aliases that a user can configure via the main GUI.

• Let the user change the displayed name of a connected snapcast client (e.g. by clicking on the name or by clicking on a small pen symbol next to the name)
• Store the user defined names so that they can be displayed after a client disconnected and reconnected
• Store the user defined names so that they can be displayed after HydraPlay was restarted