Add sample class

[ka-sarthak]

Resolves #81

[hampusnasstrom]

Sample is a very loaded name and from very long discussions from before you came, I think we decided that sample is a role. This would be something we should definitely discuss with the whole A team before moving forward on.

[aalbino2]

I believe we can skip this intermediate class, let's simply add "geometry" subsection whereever is needed, like we have in substrate, without the need of this semi-general step

What do you think?

[aalbino2]

which is the sample that undergoes a cut and needs geometry specifications here?

[ka-sarthak]

@aalbino2 @hampusnasstrom I see. Based on our discussions in today's team meet:

• getting a consensus on the term Sample will mean more discussions beyond this PR, which have already occurred in recent years.
• CompositeSystem is meant to handle samples. A possibility could be to add geometry in the CompositeSystem. However, since geometry is optional for the composite system, it should be added while extending CompositeSystem.
• In coming months, System will replace CompositeSystem, making these classes even more general. Adding geometry there is not recommended.
• Suggestion: move this class to the IKZ plugin. And the name of the class will be <Synthesis process name>IKZSample.