Use a list of predefined colors, and select the color with the larges RGB difference to the source curve. This will ensure that we avoid ending up with fully white or fully black curves, unable to see.
* Add statistics enum
* Support ensemble statistics curve as data source for regression curves
* Allow creation of regression curves from statistics curves
* Make sure regression curves are updated after source curves
* Add state to use full or user defined range for regression source data
* Add isRegressionCurve
* Make sure source stepping works when regression curves are present
* Update icons for summary and ensemble templates
* Icons for regression and decline
* #10374 LineEditor: Hide the placeholder widget when not used
* #10376 Assign a case ID to delta summary case
* Do not show decline range text in plot
