Resolve "pipeline containing a BandMath failed"

Summary

• Add missing checks on existing m_Image and m_OutputCaster
• Add C++ and python test

Rationale

Closes #1899 (closed)

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

changed milestone to %7.0.0

added bug label

dashboard is green

needs review please

added 5 commits

• 9b72708f - BUG: clarify GetImage() error message
• f07c7ead - BUG: InputImageParameter check for existing output caster
• 02d5293a - BUG: add more tests cases for InputImageParameter::GetImage()
• 608d3764 - STYLE: clang-format
• fbbbc458 - WRG: remove unused parameter name

Compare with previous version

mentioned in issue #1909

ok I have pushed a few commits that:

• Add a check for an existing caster, and raise an exception
• Improve the error message in case of multiple calls with different types
• Add 3 tests for GetImage to test the various code paths (image/filename, same/different types)

And I also opened issue #1909 to begin work on a further refactor of GetImage that does beyond fixing the original bug of this MR (#1899 (closed))

resolved all discussions

mentioned in commit 0ebe000d

merged