mrc-6066 Initial deploy tool

[EmmaLRussell]

Python deploy tool which downloads tile database files from configured packit files, and runs the grout container. Does not include a proxy. See the README for further implementation details.

I've included quite a basic refresh-all flag, instructing the tool to re-download all data files, even the ones it thinks it already has. Without the flag, it only downloads files which are missing. It would probably be more usual to want to replace particular datasets - in that case you'd probably just delete the local files in question before running the deployment.

I've also taken the somewhat cautious approach of replacing the files one-by-one when refreshing all rather than just blitzing the whole data directory from the start, so if things all go wrong at least you'll still have some data available.

Integration test and incomplete unit tests included, but not coverage.

This branch has been deployed to bots, replacing the poc container that was running there. The metadata endpoint can be accessed here: https://mrcdata.dide.ic.ac.uk/grout/metadata

The single dataset configured here is the arbomap countries dataset - a future branch will add the full gadm41 country set.

[richfitz]

Unless there's something specific in here to check, this looks reasonable and tidy and should be straightforward to update as we expand things.

[richfitz]

this looks great