export `%check||%` etc.

[mb706]

The %check||% etc. functions are useful for people implementing pipeops, in particular if they copy code from mlr3pipelines as a starting point. Migrate this into mlr3misc (or see if mlr3misc or checkmate have something like this already?)

[advieser]

As far as I can tell, mlr3misc does not have anything like it. Checkmate has %and%. However, that does not get exported and wouldn‘t handle error messages anyway.

So, I‘ll go ahead and move these and their tests to misc.