Revert "[1/3] Effects: Add a stereo widening effect"

This reverts commit a3710ad0fd5f68e91969a864f2ca58b4ae6ce2e5.
Revert "[2/3] Effects: Add center frequency param to bassboost"

This reverts commit b7874ae52fdea26a01683f4768e1214cc1b0f921.