[click_helper][ResourceOption] Allow exceptions when loading entry points

So far the ResourceOption class tried to load a string as entry points and would do this in a while loop. But sometimes an option may accept both objects and some special strings like the dask client which can be both "single-threaded", "threaded", and Client objects. Addition of string_exceptions allows for this kind of special cases to be implemented.

changed milestone to %Bob 9.0.0

mentioned in issue bob.pipelines#27 (closed)

merged

mentioned in commit 2d5b9a19

resolved all threads

resolved all threads

mentioned in commit bob.bio.base@60c135b1

mentioned in merge request bob.bio.base!220 (merged)