* using split by callsign everywhere
* helper function to insert_front
* revised linear interpolator
* renamed to remoteAircraft
* renamed to container() in providers (gettters are usually copies)
Issues why changes did so long:
* insert in list is not adding in front, but same as push_back (that was confusing)
* naming of values before/after in interpolator was ambigious
* QMap keeps values sorted by key, not arbitrarily
* consolidated ICoordinateGeodetic (e.g. fixed nested properties)
* shifted common functionality for objects/containers with callsign into interface
* shifted common functionality for objects/containers with geo position into interface
* shifted common functionality for objects/containers with timestamp into interface
* updated corresponding value objects / specialized lists
* adjusted all places where renamed functions are used
* renamed fromQVariant to convertFromQVariant, the "from" methods imply the object is changed (fromJson, fromString ..)
* implemented fromQVariant - changing the object by QVariant
* moved toQVariant into PQ template
* free function setFromQVariant
