ALSA: seq: Automatic conversion of UMP events

ALSA: seq: Automatic conversion of UMP events

This patch enables the automatic conversion of UMP events from/to the
legacy ALSA sequencer MIDI events.  Also, as UMP itself has two
different modes (MIDI 1.0 and MIDI 2.0), yet another converters
between them are needed, too.  Namely, we have conversions between the
legacy and UMP like:
  - seq legacy event -> seq UMP MIDI 1.0 event
  - seq legacy event -> seq UMP MIDI 2.0 event
  - seq UMP MIDI 1.0 event -> seq legacy event
  - seq UMP MIDI 2.0 event -> seq legacy event

and the conversions between UMP MIDI 1.0 and 2.0 clients like:
  - seq UMP MIDI 1.0 event -> seq UMP MIDI 2.0 event
  - seq UMP MIDI 2.0 event -> seq UMP MIDI 1.0 event

The translation is per best-effort; some MIDI 2.0 specific events are
ignored when translated to MIDI 1.0.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230523075358.9672-31-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>