Resolve "Simplify cloning DUNE modules and executing dunecontrol script"

What does this MR do?

Add a default dunecontrol options file build.opts and a bash script clone_dune for cloning all required DUNE modules conveniently. Updates the README.md accordingly.

Use the new clone_dune script in the Dockerfiles. Successful use of the script in the setup and prep CI stages has been verified in https://ts-gitlab.iup.uni-heidelberg.de/dorie/dorie/-/pipelines/14380 and https://ts-gitlab.iup.uni-heidelberg.de/dorie/dorie/-/pipelines/14383.

Is there something that needs to be double checked?

• After merge: Does the dorie.dockerfile work correctly?

Can this MR be accepted?

• Implemented changes
  • build.opts file
  • clone_dune script
• Added/Updated tests: Dockerfiles make use of new files
• Added/Updated documentation
• Pipeline passing
• Squash option set
• Delete branch option set
• Added entry to CHANGELOG.md

Assignee: If the Squash option is set, check/update the commit message right before merging!

Related issues

Closes #197 (closed)