Oscilloscope: 12-bit trigger support

[bessman]

In the old firmware there is an attempt to implement 12-bit resolution for multichannel capture, but it doesn't work for an unknown reason. It should be possible to get it working in the new firmware.

[CloudyPadmal]

I'm not sure if this can be implemented since we can only use CH0 channel for 12 bits 🤔

Ref: PIC24 ADC Appnote - https://ww1.microchip.com/downloads/en/DeviceDoc/70621c.pdf

[bessman]

You are right. We might be able to implement trigger support for 12-bit capture though. I'll edit the title of this issue accordingly.