…EPROJCRS

Current WKT2 grammar doesn't allow an explicit CS (Coordinate System) in the BASEPROJCRS of
a DERIVEDPROJCRS. This leads to ambiguities when instanciating the
BASEPROJCRS. Cf OSGeo/gdal#9732 (comment)
for a longer analysis

When importing such a DerivedProjectedCRS, we apply the following
strategy to try to reconstrut the CS of the baseProjCRS:
- if the baseProjCRS has an ID[], do a datebase lookup for this object,
  and if found, use its CS
- otherwise, do a database lookup from the name of the baseProjCRS, and
  if found, use its CS
- otherwise, browse through the PARAMETERs of the CONVERSION of the
  BASEPROJCRS, and if there is at least one such PARAMETER that has a
  linear unit, and if all PARAMETERs with a linear unit have the same
  one, then use it to reconstruct a Easting/Northing CartesianCS.
- otherwise, fallback to current behaviour, that is return a
  Easting/Northing CartesianCS with metre unit.

Fixes OSGeo/gdal#9732