vc: Add Volume Control Profile support

This profile should be used internally by the LeAudio or other services.
In the future it could be exposed to the application. It make sense
especially when additions to control external audio input devices e.g. MIC, HDMI,
(via Audio Inputs Control Service) and external audio speakers (via
Volume Offset Control Service)

Test: atest VolumeControlStateMachineTest VolumeControlServiceTest
Tag: #feature
Bug: 159786353
Sponsor: jpawlowski@

Merged-In: Ic4bfa5cc0f26b904c6a6767182aed31d4fabac0a
Change-Id: Ic4bfa5cc0f26b904c6a6767182aed31d4fabac0a