Replace opentopdata with (COG) GeoTIFF files

[johnjore]

Replace online GPS lookup using OpenTopoData with https://registry.opendata.aws/terrain-tiles/

Download GeoTIFF for area covered by the track/route. This allows lookup post recording of track to compare GPS and GeoTIFF data. Also, can use GPS position to lookup elevation data on status page.

This library should be usable. Its been fixed to work with the AWS data: https://github.com/fabric-io-rodrigues/GeoTiffCOG

Loop through route, and find boundaries
Convert GPS boundaries to X/Y using Z=14 (See https://github.com/tilezen/joerd/blob/master/docs/examples/collect.py#L94)
Download all TIF files for offline storage
Merge all TIF files to a single file
Loop through route and convert GPS coordinates to meters (See fabric-io-rodrigues/GeoTiffCOG#8)
Use location in meters to lookup elevation (return value is in in meters)

As we now have the TIF file offline, we can also loop through the GPS track to obtain what was actually done, vs what was planed. Can also compare GPS elevation data against TIF elevation data

[johnjore]

Convert GPS boundaries to X/Y using Z=14 (See https://github.com/tilezen/joerd/blob/master/docs/examples/collect.py#L94): Done

Download all TIF files for offline storage: Done