Support for Cloud Optimized GeoTIFFs (COG) when downloading

[munshkr]

STACInputTask should try to fetch only the relevant data from COG when providing a bounding box. Right now it downloads the whole file.

The simplest would be to leverage the new COG support on GDAL 3.1 and open the COG URLs using rasterio directly.

We could add a cog=True option on the STACInputTask constructor to indicate that it should try to open files directly instead of downloading them. Additionally it could guess if an asset is a COG file by looking up its MIME type (some catalogs include a "profile" attribute).