model_regressor discarded by dianna.explain_text and dianna.explain_image

[WillemSpek]

Problem Description

model_regressor is not being tracked by LIME's explain methods. I want to investigate the effect of the L2-regularization parameter for Ridge regression on explanations which requires this parameter.

Proposed Solution

I will add `model_regressor` as a keyword argument to the `explain` method, the method is starting to get a bit cluttered with these now though, perhaps we could get rid of `get_kwargs_applicable_to_function` `in dianna.explain_text` or `dianna.explain_image`, though this would affect the other methods as well.