implement __repr__ such that eval(repr(instance)) is an instance

[carnisj]

Implement correctly the __repr__ method in classes such that eval(repr(instance)) is itself an instance of the class.

• Implement generic functions utilities.create_repr and utilities.format_repr
• Use the generic functions in all __repr__ methods
• Add corresponding unit tests
• As a side effect, the parameter beamline from Setup had to be renamed beamline_name, because it was overlapping with the attribute beamline which is a Beamline instance

Fixes #207

Tests pass, also checked with the example dataset.

Type of change

• New feature (breaking change which adds functionality)

Checklist:

• I have made corresponding changes to the documentation
• I have added corresponding unit tests
• I have run doit and all tasks have passed

[carnisj]

Hi @DSimonne could you have a look at this PR? I would like to merge it before to avoid conflicts

[DSimonne]

I can try to have a look this week