Add colormap grouping to the preset dialog
This splits out the part of #18129 (closed) that concerned grouping of colormaps.
For these presets [presets in the advanced view], please group them by the following:
Rainbow
Rainbow like (erdc_rainbows first, rest)
Linear (dark to light, or light to dark)
Divergent (such as Cool to Warm, with white in the middle)
Convergent (such as erdc_iceFire_L, with black in the middle)
Other