The variant convertFromMemoizedJson trait did already do something similar, calling "convertFromJson" if the memoized version is not avilable. Now the function also "decides" based on the passed data itself.
* removed "IndexEnableGndFlag" as this is actually part of FSD network settings
* renamed to "isForcingVtolInterpolation"
* adjusted interpolator, and UI for setup
* min/max ground distance, also added in situation list
* use model's vtol/CG info
* improved scenery deviation guessing
* adjusted interpolator scenery deviation handling
* return interpolation results parts/situation in one step
* base class init for each interpolation step, less redundant code
* removed old interpolation/parts function
* adjusted unit tests and simulator objects (such as SimObject)
* using interface IInterpolant, renamed to CInterpolant for concrete implmentation
* CInterpolatorPBH has itws own file now, is included
* linear interpolator only re-calculates interpolant when needed (same as spline interpolator)
* use CAircraftSituationChange
* recalculate interpolant if situation changed (due to elevation update)
* keep extra info string for debugging
* improved situation checking
* split functions, added findClosestElevationWithinRangeOrRequest
* obtain elevation ids (separate ids are easier to track)
* also added experimental "physicallyAddAITerrainProbe" (FSX) for the FSX elevation probing
* callback / signal when requested elevation is received (async)
* interpolators use providers for client/situations/parts/ground elevation
* interpolators do no longer use own situations/parts, but those from provider
* interpolators are no longer QObjects (as it is not needed)
* use gnd flag from situation for gnd interpolation, there is no longer a parts gnd flag interpolation
* guess parts during interpolation
* changed iterators to m_s[i] as it makes clearer which values are used
** the flag is transferred from parts -> situation in airspace monitor
** if the other client already provides and gnd.flag in situation this also works
* adjusted logging
* use providers in unit tests / adjusted tests
* improved situation verification/assert
