Refactorings for HyMUSE, phase 1

- [ ] #1 Investigate the relation of the coupling framework w.r.t. omuse and amuse (fork or include to extend)
- [ ] #2 Docker container for pcr-glob for testing later refactorings and feedback to community
- [ ] #3 Docker container for wflow for testing later refactorings and feedback to community
- [ ] #5 Split up pcr-glob into sub-models that are being run through BMI
- [ ] #6 Split wflow into sub-models with BMI interfaces

Start by reading the referenced issues #1, #2, #3, #5, and #6 to understand the separate refactoring goals and their dependencies. Done means completing the selected coupling, containerization, or BMI sub-model task described by those issues; no files or tests are named here.

Written by the indexing model from the issue text.