POs that handle supervised tasks: do they handle derived tasks (RegrST etc) well?

[mb706]

we should check, maybe build a test case.

also: give useful error message when POs can handle only classif & regr but nothing else

[mb706]

e.g.: PipeOpVtreat

[advieser]

PipeOpEncodeImpact, PipeOpEncodeLmer, maybe PipeOpEncodePLTree
Generally, check PipeOps that have TaskSupervised as input.

[advieser]

Summary: The PipeOps listed above allow TaskSupervised as input. However, within the code we often only differentiate between cases "regr" (i.e. TaskRegr) and "classif" (i.e. TaskClassif). These PipeOps may however also work for Tasks inheriting from these (e.g. TaskRegrST from mlr3spatiotempcv), if the code is generalizable for the inheriting task types. In this case, the PipeOps methods should also handle these task types (e.g. use inherits() in the condition). If this is not the case, an appropriate error should be implemented.

TODO: check these PipeOps and either change the conditions to also accept inheriting PipeOps or throw an error. Add tests where necessary.