Resolve "Make it possible to check validity of given model parameters"

What does this MR do?

This MR allows specifying default values and types for scalar parameters in the model_cfg.yml; before a run, the model parameters will then automatically be checked against these defaults. Parameters requiring validation are marked using either a !param tag or one of several shorthands, and are extracted as a custom Parameter class object. Possible validation failures are outputted in a legible and concise way, allowing users to pinpoint the cause of the error.

Can this MR be accepted?

• Implemented the changes
• Added or extended tests
• Checked test code coverage on new and adjusted code
• Added or updated documentation
• Reasonably up-to-date with current master
• Pipeline passing without warnings
• Squash option set
• Approved by @blsqr
• Approved by @tgaskin
• optional Approved by @peanutfun @herdeanu @JulianWeninger

Related issues

Closes #35 (closed)