Mcstasscript on libpyvinyl

[mads-bertelsen]

Version of McStasScript that use libpyvinyl base classes, uses new syntax so breaks backward compatibility.

Parameters inherit from the libpyvinyl Parameter class ParameterContainer inherits from the libpyvinyl CalculatorParameters class McCode_instr (main class) inherits from libpyvinyl Calculator class

An example of the new syntax is shown in examples/libpyvinyl_example.ipynb

The work is not complete, there are still some tasks before a merge is possible

• [x] Check if dump / load works and add new unit tests.
• [x] Check if parameters can be given when loading from dump
• [x] Consider how output_path should be implemented
• [x] Old unit tests have to be updated.
• [x] Documentation needs to be updated

This pull request exists so that others can comment on the implementation and we can discuss how to best proceed in a way that aligns with the pyvinyl project.

[mads-bertelsen]

Updated to run on libpyvinyl 1.1.0 and documentation in good shape at https://mads-bertelsen.github.io. Ready to merge!