Replaced single palette cases with an array to consolidate code

[DedeHai]

• all palettes are now defined in palettes.h
• access to fastled palettes as an array to remove the switch cases
• palette creation in json.cpp in a loop instead of repeated calls to save some flash (about 300 bytes)

[blazoncek]

It might also be beneficial to completely remove FastLED dependency and include/duplicate its palettes in WLED.
IMO FastLED is loosing foothold in WLED (if you will implement your other FastLED replacements).

[DedeHai]

there are a few other functions used from fastled: CRGB and 8-bit math functions for example. I am not sure there is much benefit from copying all those functions instead of using the library but I may take a closer look once all the PRs are merged.

[blazoncek]

qadd8(), sin8/sin16(), random8/random16() I think you touched all of them at some point.
Other that are used are overloaded operators (i.e. + etc) which operate on struct CRGB (which you also touched).

I am not saying that it is necessary to replace the library, I am just thinking out loud about possibility to replace library since you already ventured into those waters by replacing some of the functionality of FastLED.