Make airport charts UI consistent with maps

[mjh65]

From @dave6502: "In the past, without chart georeferencing, this wasn't an issue. But now, the charts in the AirportApp feel more like a Map. So any features in the MapApp that are "missing" from the AirportApp are now a minor inconvenience - e.g. overlay config settings, hotspotting, AI aircraft. It would be nice, but not a priority, for the AirportApp to leverage the same features."

Recording this since it may be a while before I get time to look at this.