Better method for translating raster data.

[ablakey]

Currently because of https://issues.qgis.org/issues/19252 the method for getting a raster message (like OccupancyGrid) and converting it to a GeoTIFF is done with an external process. This works, but is kind of clumsy. Consider better ways to handle this with or without a resolution to why doing so within the process causes a segfault.