Assign a color to POI category and enable to highlight different POI category if they have different color about osmand

[scaidermern]

Partly related to #16304.

[binoyte]

For the following, I call "meta-category", saved POIs searches, or custom POIs categories

According to me the request should be :

1. Allow customization of existing categories (color, shape and icon)
2. Allow customization of "meta-categories"
3. Allow "meta-categories" to specify whether or not they can overload POIs customization by their own.
4. Allow "meta-categories" to specify whether or not they can overwrite POIs customization by their own.

Then several cases :

1. A meta-category is just as now, a group of existing categories, with no modification of their look.
2. A meta-category shows existing POI, in a different way, without editing their own customization.
3. A meta-category allows bulk changes of existing categories look (mass editing).

Examples :

1. Sources in blue. Campsites in green. My custom category "myHiking" doesn't change their look.
2. Sources, taps etc. are orange by default. My custom category "MyWater" shows them in blue. I choose if these categories stay orange, or if I overwrite their color by myHiking's color. In both cases I see them in blue, MyWater's color.