Fixes HF when forgetting more than available devices
Reworked AppSettings handling of BT devices to be prepared for handling the HFP profile, eliminating by the way few bugs and speeding up the flow (by getting rid of few refreshes). Added unit tests for handling the BT devices flow
Defined separate cmake target, dependencies, private, and public sources, cleaned up include paths
Bluetooth setting cleanup.
Bartosz Cichocki