Add dedicated application to compute ground and satpos from precise orbit

This issue is a sub task of s1tiling#151 (closed).

The objective is to create a new OTB application

• that reuses SARDEMProjection2 code related to -withxyz, -withsatpos and that supports DEM in any spatial reference
• that decodes OSV data from EOF files to construct FastSarSensorModel accordingly

Let's name it SARComputeGroundAndSatPositionsOnDEM, name that matches the step name used in S1Tiling.