Implementation of "wrapper" methods

[pat-s]

Sticking closely to the implementation in mlr3tuning.

Methods

Ported from what we have in mlr.

• Exhaustive search makeFeatSelControlExhaustive

• Genetic algorithm makeFeatSelControlGA

• Random search makeFeatSelControlRandom

• Deterministic forward or backward search makeFeatSelControlSequential

cross-ref #2

[pat-s]

mlr3tuning uses the AutoTuner class as a wrapper for automated tuning in nested resampling.
We should also implement the wrapper methods in a class AutoSelect (or a similar name) to stay consistent.

[mllg]

AFAICT all methods are implemented (not reviewed though) in mlr3fswrap. Closing here.