Update raster exporter to also support COG (cloud optimized GeoTIFF)

[neteler]

In the raster exporter currently there are hardcoded GeoTIFF settings:

https://github.com/mundialis/actinia_core/blob/8353b231c1a475955f68e4484e329c7d74b292e0/src/actinia_core/resources/ephemeral_processing_with_export.py#L251

Since GDAL 3.1+ there is a new COG driver which works nicely with r.out.gdal.

Wish: add COG driver support and use it if present. This would require a test:

r.out.gdal -l
  COG (rw): Cloud optimized GeoTIFF generator

• if COG driver present, use it for r.out.gdal export:
  • r.out.gdal -m input=mymap output=mymap.tif format=COG
• if COG driver not present, use the current GeoTIFF based r.out.gdal export.

[mmacata]

Isn't this implemented by #108 ?

[neteler]

Yes - the PR wasn't linked.