First working versions of TpvGUIColorWheel and TpvGUIColorPicker in the PasVulkan GUI subframework

First working versions of TpvGUIColorWheel and TpvGUIColorPicker in the PasVulkan GUI subframework, where the whole triangle color wheel is rendered by the GPU itself only with two GPU-triangles with help of fragment-shader-side 2D signed-distance-field-stuff, and  where it can be also controlled purely with the keyboard.