Resolve "Implement new parameterization data input"

What does this MR do?

Add new options for the input of paramterization data and its attachment to the grid. The old options are removed.

• Add GridCreator for building grids.
• Add GridMapper which is called by GridCreator for load-balancing the grid and the mapping data.
• Upgrade H5File to read datasets with arbitrary H5 data types.
• Merge !55 (merged) into this.
• Implement reading a YAML parameterization file in FlowBoundary.
• Add unit tests for the new classes and functions (use !98 (merged)).
• Adapt system tests.
• Add (at least preliminary) documentation on usage of new features.
• Add pygmsh and h5py to virtualenv.
• Move creation of GridWrapper out of RichardsSimulation, see #97 (closed).
• Update docstrings of new classes and RichardsSimulation.
• [ ] Optional: Rename GridWrapper, see #97 (closed).
• Remove old parameterization and method run() (See https://ts-gitlab.iup.uni-heidelberg.de/dorie/dorie/merge_requests/89#note_14708).
• Remove old parameterization source files.

Additional performance tasks

• Replace calls to MPI with calls to Dune::CollectiveCommunication.
• [ ] Optional: Instantiate objects for GridCreator, GridMapper, and H5File explicitly. Remove template parameters where possible.

Is there something that needs to be double checked?

Not sure yet.

Can this MR be accepted?

• Implemented new features
• Added new tests
• Adapted tests
• Removed testing executables
• Pipeline passing
• Added docs
• Added entry to CHANGELOG.md
• Update README.md

Related issues

Closes #86 (closed)

Meta-issue #63 (closed)

See also #97 (closed)