#14227 Compute depth-related geometry results once for both porosity models

The depth-related geometry results (DEPTH/DX/DY/DZ/TOPS/BOTTOM) are derived
purely from the shared grid geometry and were computed independently for the
matrix and fracture porosity models. For dual-porosity cases this recomputed the
identical per-cell geometry twice.

Replace the per-model computeDepthRelatedResults() with a single static routine
that traverses the shared main grid once, computing each cell's geometry a single
time and writing it to every porosity model in which the cell is active. The
per-property already-computed guards and the temporary-grid recompute path are
preserved, so the stored values are unchanged. All six matrix+fracture call sites
now go through a thin RigEclipseCaseData::computeDepthRelatedResults() wrapper.

ApplicationLibCode/ProjectDataModel/RimRoffCase.cpp

@@ -99,8 +99,7 @@ bool RimRoffCase::openEclipseGridFile()
 
     if ( RiaPreferencesGrid::current()->autoComputeDepthRelatedProperties() )
     {
-        results( RiaDefines::PorosityModelType::MATRIX_MODEL )->computeDepthRelatedResults();
-        results( RiaDefines::PorosityModelType::FRACTURE_MODEL )->computeDepthRelatedResults();
+        eclipseCaseData()->computeDepthRelatedResults();
     }
 
     results( RiaDefines::PorosityModelType::MATRIX_MODEL )->computeCellVolumes();