Embryonic GPKG raster reading

git-svn-id: https://svn.osgeo.org/gdal/trunk@28022 f0d54148-0727-0410-94bb-9a71ac55c965
Fix crash triggered by misc.py

git-svn-id: https://svn.osgeo.org/gdal/trunk@28023 f0d54148-0727-0410-94bb-9a71ac55c965
Merge branch 'trunk' into trunk_vc12