This removes all redundant code and improves the logic of the biquad filter.
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3235
Reviewed-by: Maufeat <sahyno1996@gmail.com>
Co-authored-by: MaranBr <maranbr@outlook.com>
Co-committed-by: MaranBr <maranbr@outlook.com>