RGBW Support in Display Testing and Overlay Pixel Models

[OnlineDynamic]

Placeholder for fpp10 functionality

Would be good to allow fpp to properly handle RGBW (4 channel) Display Testing

"E1.31 / ArtNet / DDP / KiNet" outputs -e.g. wireless floods - would be good if the pixel overlay models understood the RGBW order

[darylc]

pinged Stuart to merge this to master

[OnlineDynamic]

@patdelaney do you have some rgbw pixels that you could use to test this on the new feature branch for me?

[patdelaney]

Yes I do

[OnlineDynamic]

This has now been merged to master