Review change detection examples

Summary

• Review all examples in ChangeDetection/. Add figures, clean-up code and comments, write description in rst, etc.

Rationale

Part of #1865

Copyright

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

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