Revert "Revert "[3/3] AudioFX: Add center frequency param to bassboost""

This reverts commit fc2a35e9175f4cfe192dd4fe85d5e1df0cede8ba.
Revert "Revert "[3/3] AudioEffect: Add a stereo widener effect""

This reverts commit ac117455d8888bddc438343c7f901bb7c1e1edbf.