Why is `send` always overwriting `MIDIMessage.channel`?

Just curious, but why is `send` forcing a `channel` on a message ([here](https://github.com/adafruit/Adafruit_CircuitPython_MIDI/blob/main/adafruit_midi/__init__.py#L155)) even if the message had its channel field set explicitly? Isn't the main point of the message having a "channel" field in being able to prepare a set of messages assigned to different channels and have the MIDI interpreter send them to those channels, exactly as given?

Sure, I could always make sure to write `midi.send(message, message.channel)`, but this now seems to defeat the purpose of the `send` method's channel argument (and the `MIDI` object `out_channel` field) in being able to configure an `out_channel` as some sort of a default when necessary.

A more meaningful design, IMO, could be:
* Whenever a parameter is passed to `send`, use it.
* Otherwise, use `MIDIMessage.channel`, unless it is None.
* ... in which case fall back to `MIDI.out_channel`.

Start with the send implementation in adafruit_midi/__init__.py around line 155 and read the issue's proposed channel-precedence rules alongside the MIDIMessage and MIDI out_channel behavior. Determine the intended precedence, check existing callers, and define completion as an agreed and tested behavior that preserves the documented default-channel use case.

Written by the indexing model from the issue text.