DmxInput: start_channel is not honored

[MatheusMeM]

Pico-DMX lib

Problem:
The lib does not handle initial address changes. it only register from the start address till NUM_CHANNEL set in.

Original Issue: jostlowe/Pico-DMX#15

Possible Solutions:

1." I wouldn't know a proper solution to tell the PIO state machine OR the DMA to ignore the first X bytes. Of course, we could let the DMX write into an intermediary buffer and then copy only the requested channels to the buffer provided by the library user." - kripton
WIP: https://github.com/kripton/rp2040-dmxinput/tree/a85e14eff7f862e1d2a70787792a0db6b923d446

2. DmxInput improvement: Trigger the IRQ not based on number of received bytes but on the state of the line
   DmxInput improvement: Trigger the IRQ not based on number of received bytes but on the state of the line jostlowe/Pico-DMX#21

3. DMX for PICO without PIO
   DMX for PICO without PIO jostlowe/Pico-DMX#25

4. Alternative Method I
   https://github.com/opsnlops/parrot-controller/blob/main/src/io/dmx.cpp

5. Alternative Method II
   https://groups.google.com/g/open-lighting/c/zLR86ElhXmw?pli=1