Allow per-light temperature correction

This is similar to part of what was asked for in #124, which got closed as a duplicate of the other feature it asked for; meanwhile this feature request as far as I know was forgotten. Some of my lights are high quality and others are not. The low quality ones claim to have a certain temperature range but fall pretty short of it, so that when the lights are all told to be the same temperature some are visibly much cooler than others. Borrowing @RubenKelevra's photo from the linked issue to illustrate: >  There is a suggested remedy in the readme: > To resolve this: > > 1. Include only bulbs of the same make and model in a single Adaptive Lighting configuration. > 2. Rearrange bulbs so that different color temperatures are not visible simultaneously. That's not really a solution in my opinion. And in my case I can't just swap out the custom-cut LED strips I've installed. (Though I learnt my lesson not to cheap out on RGBCCT strips again in future.) Currently (I've only just started my switch to home assistant) I have a script which runs through all my lights with a target temperature in mind and for most it sets that target temperature, but for some others in particular groups it does a transformation on the target temperature first. The way I implemented it is to set two anchor temperatures: "if I ask for 3500, be temperature x instead; if I ask for 6500, be temperature y instead; interpolate linearly between those". It does a decent enough job. I'm hoping something similar might be possible here.