Add RGB color support

[werneckpaiva]

This change enables the the library to handle RGB color values. It seamlessly integrates with existing handlers, maintaining backward compatibility for those that don't utilize RGB functionality. It supports hue/saturation and color temperature (shades of white) formats used by Alexa.

[pvint]

This looks awesome @werneckpaiva !!
I've been meaning to get back to this for ages... but for some reason never came up with a good solution. Thanks so much!

I'll try to test over the next day or so, but I may get delayed, so if anyone else tests please let me know.

Paul

[werneckpaiva]

Great Paul! I also found the PR from Spencer (#207), which is a bit outdated now, but it has some intersting ideas, specially when reporting the status back to Alexa. I will also try to create another PR adding it.

[pvint]

@werneckpaiva Could I trouble you to change byte variables to char (or whatever makes sense) please? Just want to keep compatibility with ESP-IDF which doesn't use byte

[pvint]

I'll go ahead and merge this and I'll take care of the changes from byte after. Thank you again @werneckpaiva for this!