[DEE-206] [feat] Allow Users to Create Checks On the Fly about deepchecks HOT 1 OPEN

Since this proposal we had some thoughts on the matter, trying to outline some of them:

1. The tricky part would be how does the user generate a display. Current example only shows how to return a value. We need him to be able to return a display object which is (as we do it now) either text, dataframe or callable (that prints matplotlib). doing only this - adding a custom check that prints something and nothing more - is the most basic part and should be easy.
2. Additional functions, such as having a return value and defining a condition on it could be more complicated, the logic being that if you're implementing a check & condition then it's for CI / CD ish purposes and you can and should invest more time doing it right.

from deepchecks.