* WebService: Verify username and token; Log errors in PostJson

* Fixup: added docstrings to the functions

* Webservice: Added Icons to the verification, imrpved error detection in cpr, fixup nits

* fixup: fmt warning

* Initial Commit

Added Device logic to Sinks
Started on UI for selecting devices

Removed redundant import

* Audio Core: Complete Device Switching

Complete the device switching implementation by allowing the output
device to be loaded, changed and saved through the configurations menu.

Worked with the Sink abstraction and tuned the "Device Selection"
configuration so that the Device List is automatically populated when
the Sink is changed.
This hopefully addresses the concerns and recommendations mentioned in
the comments of the PR.

* Clean original implementation.

* Refactor GetSinkDetails

* implement frame limiter

* fixes

Fixes #1960.

Allows users to choose a single screen layout or a large screen layout.
Adds a configuration option to change the prominent screen.