A2DP: HAL codec offloading capabilities check preparation

* Move HAL codec properties to ::bluetooth::audio::codec namespace
* Add API to query the audio HAL capabilities about codec offloading
* API for Applying frameworks offloading preference
* API to check whether the codec configuration is offloading or software

Bug: 143922003
Test: bluetooth-test-audio-hal-interface
Change-Id: I47ce39ada6eed696bc1b8771cda6a52fd8a30e60