Allows raster pixels to be labeled with the value taken from a raster
band.
Labels are registered with the labeling engine, so participate in
label conflict resolution and overlap avoidance
Options include
- Selection of band to take values from
- Using QgsNumericFormat to customise the number format for the labels
- Uses text renderer, so supports buffers, shadows, etc
- Label priority
- Scale dependant visibility
- Optional pixel size dependent visibilty, ie show only when pixels are
> 4mm in size
- Z index control, overlap avoidance mode
Fixes#14408
