Verify source of downloaded geodb

[AuroraLS3]

I would like to be able to..

Ensure that geolocation database is downloaded from trusted Plan webserver.

Is your feature request related to a problem? Please describe.

MaxMind reduced downloads to 30 / day, the geodb download was moved to playeranalytics.net

To future proof the plugin against domain takeover the download should check a file signature.

I had trouble verifying stuff with Java so this got postponed since the geodb breakage deadline came faster than implementation was ready. I'm opening this ticket since I'll forget otherwise.