Missing RAM parameter in StereoRectificationGridGenerator application

Summary

StereoRectificationGridGenerator application tries to use the -ram parameter which is not a parameter of the application:

https://gitlab.orfeo-toolbox.org/orfeotoolbox/otb/blob/develop/Modules/Applications/AppStereo/app/otbStereoRectificationGridGenerator.cxx#L306

This MR adds the RAM parameter and add a test to check the mode of the application using it.

Copyright

The copyright owner is CNES and has signed the ORFEO ToolBox Contributor License Agreement.

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Check before merging:

• All discussions are resolved
• At least 2 votes from core developers, no vote.
• The feature branch is (reasonably) up-to-date with the base branch
• Dashboard is green
• Copyright owner has signed the ORFEO ToolBox Contributor License Agreement
• Optionally, run git diff develop... -U0 --no-color | clang-format-diff.py -p1 -i on latest changes and commit