main/puremaps: new aport

Our first GPS app! 🎉 This took way longer to package than I wanted, but hey here it is. Although it seems to run with 1GB of RAM, osmscout-server killed itself once due to lack of memory. 2GB of RAM or more is recommended for now.

PureMaps has both online and offline navigating. Online navigating requires the user to provide API keys for the services being used. We could provide those from postmarketOS in the package, but there is only a limited number of free (gratis) calls and then we'd have to pay so I'm against that. If the user wants online navigation, it is explained in the app how to get their own API keys so they are free to do that.

Alternatively you can navigate completely offline using the osmscout-server package. With this application you can download maps for offline usage, and when having it running in the background it will be used to search for addresses and calculate routes.

Current issues:

• Some icons are missing

* [ ] When using offline navigation, the user has to manually launch osmscout-server as it normally uses a systemd feature to auto-launch it which we obviously do not have

• I haven't actually tried this with a device with working GPS, I doubt it works out-of-the-box. Needs testing