obs/generic/: Improve MCA compilation. Fix some bugs. Add, clean and update distribution and compilation files or templates.

obs/generic/templates/compilation-templates/mca/: Improve MCA compilation. Copy more files from it.
- Fix and improve the Makefile.
- Copy more things from openssl(-dev), i.e. everything except the links to the certificates (in parts/ca-certificates/).

build-scripts/clean_build_tree.sh: Fix failure when $RUN_BUILDOUT_DIR/go did not exist.
build-scripts/bootstrap_buildout.sh: Fix a bug in the backup mechanism.
templates/:
- Fix compilation-templates/mca/Makefile.in
- Change distribution-templates/debian_defaults/dirs.in to fit the mca case.

distribution-specifics/:
- Change the "Version" field in the .dsc
- fluent-bit: Add distribution-specifics clean the compilation templates.

Add support for dep--mca: MCA with light build dependencies.
- Add distribution-specifics/dep--mca/
- Add templates /compilation-templates/dep--mca/

Add support for dep--mca--static: Statically linked MCA ith light build
dependencies.
- Add distribution-specifics/dep--mca--static/
- Add templates /compilation-templates/dep--mca--static/

Add support for dep--fluent-bit: fluent-bit with light build
dependencies.
- Add distribution-specifics/dep--mca/
- Add templates /compilation-templates/dep--mca/