REFAC: update baseline for Homologuous point extraction tests (max error is less than 1cm in both tests)

Merge branch '2040-RPC_model' of https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb into 2040-RPC_model

REFAC: update baselines for dmTvStereorectificationDisplacementFieldSource (RPC refactoring), the test currently fails with a 1e-10 tolerance but succeeds with a 1e-9 tolerance

REFAC: update baseline for prTvImageToGenericRSOutputParametersOutput (1e-7m diff in the UTM31N spacing caused by the RPC refactoring)

ENH: implements an observer pattern to keep track of DEM configuration changes in GDALRPCTransformer

Remove OSSIM dependency from SensorModel tests

See merge request !778

ENH: Improve QGIS interface for ExtractROI application

See merge request !767

Improve qgis parameter integration

See merge request !768

The SensorModel tests use OSSIM to generate the reference values.
I removed this dependency to OSSIM, but I added the values to the
Input, so we can still compare the results to OSSIM's values.