Fail if ParamFunctions depends on ColumnObjects

[MImmesberger]

What problem do you want to solve?

Closes #999

Fails if any param_function depends on a ColumnObject, with the exception being evaluation_x and policy_x (they are PolicyInputs).

[codecov]

Codecov Report

❌ Patch coverage is 91.66667% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ests/ttsim/interface_dag_elements/test_failures.py	85.71%	3 Missing ⚠️

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[hmgaudecker]

Very nice, thanks a lot!!!

Given the architecture, we cannot grant exceptions for dates, that would lead to errors when trying to use actual columns as dates. However, the two cases where we had that in GETTSIM actually should be policy_dates IMO. That is, it does not make sense to ask for the policy environment of 2020 but then evaluate it at the parameters for the introduction of the Vorsorgeaufwendungen of 2010. Put differently, in those cases we only use the piecewise polynomial to define the correct policy environment based on the date. Very different when we are talking about age/cohort-based rules.

Other than that, I just made some simplifications to the code.

[MImmesberger]

That's a bit different from what I was trying to sell before (policy_environment being a snapshot from the text of the law), but if it makes our lives easier its reasonable I'd say.