Improve local GeoTIFF support

[martinRenou]

#571 restored local geotiff file support.

We should see if we can build a URL for the local file and use COG instead of loading the full file.

[mfisher87]

We'll need to check if the GeoTIFF is cloud-optimized first, e.g. by checking for the right tiff tags.

rio-cogeo can do this from the CLI.

I found is-cog for doing this in JS-land, but it's pretty old. It has some open issues and the author replied as recently as 2024.