[Cin] ChromakeyHSV menu much improved

[Andrea paz]

> P.S. Someone indicated that ChromakeyHSV had some kind of bug, but I was wondering if Andrea ever found out exactly what that was? since it looks OK to me.
>
Great job; thank you!
One problem with the plugin can be seen in the following video:
https://streamable.com/yyze7y
In practice, "Min Saturation" behaves like "Saturation Offset" when in
fact it should behave as in the following figure:
https://postimg.cc/HjZDcvr2
(Min Sat should form a new smaller wedge [dotted line], instead it
creates an arc without more spike, which is the right behavior of Sat
Offset).

However, I always hope that we will be able to integrate Adam's new
plugin, which is a great evolution of ours and works very well.