multimedia/audacious-plugins: Enable AMIDI and JACK options by default

On user request enable AMIDI by default.

Since this adds a dependency on audio/fluidsynth which, by default,
also depends on jack, enable jack here too.

PR: 282186
MFH: 2024Q4
(cherry picked from commit 73054fd089ab8f7c9d918e3c5a14195a362bbf2d)