Add an exchange module for the MCT

[AntoniaBerger]

Fixes #252

Work structure:

• Create a new exchange modul. #256
  • New Base class 'IPhaseTransition Model'
  • New class 'LinearExchange'
  • Add to CMakeList
  • Add the linear exchange to the MCT model. #262
  • Compare exchange modul results with implemented version.
• Add exchange as a part of the MCT modul
  • make exchange parameter parameter part of MCT
  • ubdate parameter handler for phaseTransitionModel
  • Test results
• Outsourse Iteration and declaration for residual and Jacobian?

[jbreue16]

I had a couple of minor remarks that need to be addressed before merging.

I thought about adding a dummy Exchange (similar to what we have for binding), but decided against it since there should always be some exchange in the MCT, as using that model doesnt make sense without.

Tests still work, so I'll approve this PR to be merged after minor revision.
It would still be interesting if the abstraction layer has any influence on the performance of the MCT. A benchmark would be nice, comparing the old and new implementation wrt computational performance.

[schmoelder]

Thanks @AntoniaBerger for your first major contribution to CADET-Core. Before merging, please add documentation and interface specifications. Also, please try to clean up the commit history a bit.

[jbreue16]

Before merging, please add documentation and interface specifications.

Modeling and interface has not changed, this PR only changes the infrastructure in preparation of the changes in #271 , which will have implications on modeling and interface

Also, please try to clean up the commit history a bit.

I think we can just squash and merge all of this into one commit, or do you knwo some logical chunks, which all run and work, we can separate this into @AntoniaBerger ?

[AntoniaBerger]

Not sure, but I think one commit will be enough.

[schmoelder]

Thanks for the clarification.

resolved