Support (N)RPN midi IO

[grrrwaaa]

Per thread here: https://forum.electro-smith.com/t/is-there-an-nprn-encode-decode-supported-by-default/1669

Some notes from the thread:

• NPRN Type are the CCs: 99 (MSB) and CC 98 (LSB), as you noted above
• NPRN Data/Value are the CCs of: 6 (course/MSB) and 38 (fine/LSB) for the values.
• https://en.wikipedia.org/wiki/NRPN
• https://www.elektronauts.com/t/nrpn-tutorial-how-to/46669
• https://cycling74.com/forums/how-do-i-nrpn There are "nrpnin" and "nrpnout" objects in vanilla Max.

Seems like this could be prototyped using existing CC handlers in oopsy, and a bit of math for the MSB/LSB handling, and some logic for the possibly sequential nature.

If it seems solid and workable, it should be feasible to create e.g. param midi_nrpn_XYZ and history midi_nrpn_XYZ_out etc., where XYZ refers to the NRPN type.

I note that I've seen some quite inconsistent and strange uses of NRPN by different hardware, so I'm a bit hesitant to push for something that might be an endless series of cases that don't work... but I admit I've never really dealt with them so maybe there is a generalized and flexible pattern that can be used.