Allow use P9813 with WW+CW led strips.

[zcaliptium]

Problem

P9813 is a really cool ready to use driver. But nowadays WLED allows only using it for RGB strips, so there is no way to say that it controls piece WW+CW strip.

Solution

Put option like "P9813 WW+CW" as LED type. Then allow to bind it to any of three channels.

It will be the best solution if we will just have something like:

• Channel 1
• Channel 2
• Channel 3

And then selector for color that corresponds the color - Red, Green, Blue, Cold White, Warm White. In a same manner as it is done for DMX channels:

[blazoncek]

If you know how to code your best bet is to implement it in a similar fashion as WS28xx WWA strip which I implemented a while ago, available in 0.16.