[next] autoswitch-bluetooth-profile: remove applications array and use loopback filter

This patch improves the bluetooth profile autoswitch so that it works with any application that wants to capture from a bluetooth device. To do so, a loopback source filter is created per connected bluetooth device. If an application wants to capture audio from such loopback source filter, the profile in the associated bluetooth device is changed to HSP/HFP. If there isn't any application connected to the loopback source filter, the profile switches back to A2DP.