Roadmap to common main and paper

Requirements for merging to main:

• address issues raised in the original PR
• make sure C++ tests pass in !5 (closed)
  • (for Tim & Felix:) as soon as this works, Felix starts on LRBMS C++ example
• make sure Python bindings compile in !5 (closed)
• make sure Python Tutorials work with !5 (closed)
  • (for Tim & Felix:) as soon as this works, Tim starts on LRBMS Python tutorial
• merge !5 (closed) into main

Afterwards (new issues to be created yet), roadmap to paper:

• ensure wheels can be built and are importable
• update C++ functionals to match operator refactoring
• update Python bindings to support new syntax after refatoring
• add Python tests
• pyMOR LRBMS discretizer