Deploy Doxygen documentation in CI

Summary

Documentation for otb is generated during merge request builds (when code is pushed in a branch with an associated MR) and develop builds (when a branch is merged into develop). The html documentation is available as .tar at https://www.orfeo-toolbox.org/packages/ci/

For develop builds the Cookbook is automatically un-tarred and is available at https://www.orfeo-toolbox.org/CookBook-develop/

This is not the case for the Doxygen documentation. This merge request adds the required command in CI scripts to deploy the Doxygen documentation.

Additionally a link for the develop doxygen has been created on the website https://www.orfeo-toolbox.org/doxygen-develop/

Links to the develop documentation has also been added to the Download page of OTB (see the Develop Binary Packages section).

Additional notes

Note that the changes can only be tested by merging this branch in develop. Please review carefully ! I tested each command locally.

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