Add support for stream deck pedal without visuals

[moenzuel]

Supporting the pedal seems straight forward enough. It doesn't have visuals so block out most of the commands. Adding just this allows basic support in the downstream deckmaster. I'm not sure on the featureReportSize but 32 seemed to be enough.

n.b. I don't normally write Go code so I may have done something terrible too.

[muesli]

Thanks for the PR, @moenzuel! The change looks sound, I just haven't had a chance to try it out with actual hardware (delivery got delayed by several weeks).

[moenzuel]

Gave this an update on the chance this can still merge

[chrisbward]

Hi @muesli and @moenzuel - I can give this a try!

How do I target the pedal in deckmaster alongside a streamdeck?

[muesli]

I think what @moenzuel did here seems fairly appropriate. Disappointingly I never received my testing hardware from Elgato, so I had no chance to test this.

@moenzuel Looking at the code, the pedal seems to "imitate" a device with 3 buttons?

[moenzuel]

@muesli Yes, it acts the same as a standard stream deck but with only 3 buttons and no displays.

[chrisbward]

Yeah, code does seem good - I just wonder how deckmaster is geared to handle mutliple devices, or would I just run two instances with a flag, @muesli?

[chrisbward]

ahhh from deckmaster docs;

deckmaster -device [serial number]

nice! I will set up and report back later today, thank you

[muesli]

Correct, I'd suggest using a separate instance per device, using the -device flag.