Enforce all 3Di raster requirements.

[leendertvanwolfswinkel]

There are some requirements to 3Di rasters that the RasterCaster does not currently enforce: valid filenames, projected coordinate system, maximum of three decimals on pixel size, output raster projection equal to global settings EPSG code, and identical data/nodata pixel locations between input rasters. Giving the user the option to enforce these constraints will guarantee that the rasters are usable as 3Di input without any problems. Another useful addition would be to constrain the output raster to active pixels in the base raster or another reference raster, to ensure that the new raster remains compatible with other existing rasters in the 3Di model.