📝 Polish Interactive Tutorial

[ystade]

#330 provided a solid foundation for the interactive tutorial requested in #310. There are still some improvements that could be made to the tutorial. This issue collects all of these improvements in a comprehensive way.

tutorial.md

• The code style in the c++ examples should be adapted to the one used across the project, i.e., if-branches without braces
• Rethink the making of components driver, user, client with respect to the upcoming changes to QDMI
• Check the test suite whether all potential cases in the documentation are covered, make it rigorous
• Make every checkpoint an individual test case meanwhile make the verification commands constant, i.e., use checkpoint-X everywhere instead of e.g. Init
• Create more links to existing docs

[Bmete7]

It's a very minor point, but on the tutorial documentation all the hyperlinks under the checklist: "Your Progress Journey" leads to the top of the page for me. Maybe the referenced points are broken?