FILTERS: Add a new way to compute the lowpass output for the Moog

For documentation purpose.

Signed-off-by: G4m4 <misept.dieseneuf@gmail.com>
FILTERS: Clean the way naive oversampled Moog filter prototype was handled

Now using its own subclass.

Signed-off-by: G4m4 <misept.dieseneuf@gmail.com>
SCRIPTS: Add minor comment

Signed-off-by: G4m4 <misept.dieseneuf@gmail.com>
SCRIPTS: Add minor (commented out) way to get filter gain

Signed-off-by: G4m4 <misept.dieseneuf@gmail.com>
FILTER: Tune tests in order to make the low alias Moog filter pass them.

Signed-off-by: G4m4 <misept.dieseneuf@gmail.com>