feat: add MIDI map editing

(hihiiii! a lot of small tweaks among the large tweaks, will try to cover everything but please lmk if anything remains opaque!!)

this PR adds:

UI for editing MIDI mapping
allow_pmap flag
MIDI echo back to mapped devices
support binary-type parameters in UX/UI
examples/hello_pmaps.lua to demonstrate!

MIDI map UI

while in mapping mode, press ENTER on any mapped parameter to open the mapping for editing:

here, you can manually modify:

cc number
channel number
mapped device
out: lowest parameter value (scales incoming CC value to this range)
out: highest parameter value (scales incoming CC value to this range)
in: lowest incoming value (any CC lower than this value will not affect the parameter)
in: highest incoming value (any CC higher than this value will not affect the parameter)
accum: enable when using relative / delta-based CC streams
echo: enable to send the parameter's (scaled) value back to the mapped controller (for LED activity)

key nav:

left/right: navigate mapping
up/down: delta +/- 1
right ALT + up/down: delta +/- 10
TAB: cycle to next parameter
SHIFT + TAB: cycle to previous parameter

`allow_pmap` flag

by default, every action-based parameter (except text) is MIDI mappable. this can be changed via the allow_pmap flag, eg:

params:add {
    type = "number",
    id = "unmappable_number",
    name = "you cannot map this!",
    min = 0,
    max = 10,
    default = 0,
    allow_pmap = false,
  }

params:add_number('unmappable_number', 'you cannot map this!', 0, 10, 0, nil, false)

this flag prohibits mapping in both the map mode:

and the mapping editor, if TAB'd over:

MIDI echo

as part of the MIDI mapping editor, you can specify whether the parameter's current value should push back to the mapped device. this is useful for devices like the MIDI Fighter Twister which have CC-addressable LED's on each encoder. when a PMAP is loaded, any echo-enabled parameter will redraw to the mapped device.

support binary-type parameters in UX/UI

previously, the binary parameter type wouldn't register in the UI and keypresses wouldn't register state changes. this has been addressed (w/ the same qt lil' squares as norns)!

`hello_pmaps.lua`

it's in there!

robbielyman / seamstress