Relocation of Tileserver

[docuracy]

TileServer-GL is now offered as a Docker image, and has the capability of running a proxy server to fetch individual tiles out of an mbtiles file stored on DigitalOcean Spaces. It can be configured to work with DigitalOcean or AWS, but not with Google Cloud Services.

Proposal (to be costed)

• Move the tileserver to an additional Docker network on the whg3 server.
• Use object storage on DigitalOcean Spaces for all of the mbtiles, and for database/index backups.

Relying on one server remaining healthy instead of two could be advantageous, and by having everything Dockerised we could tweak the number of instances of each service (in the compose files) if any were to become frequently overloaded, and up/down-scale the server as and when necessary.