Add a setting to display Media-Image Descriptions

@thomas.frobieter the alternative would be to be able to select the media image viewmode to use. Has advantages and disadvantages, just leaving this here as note.

Feel free to start implementing the UI part of this checkbox, whenever we really need it (= someone pays for it)

@thomas.frobieter the alternative would be to be able to select the media image viewmode to use. Has advantages and disadvantages, just leaving this here as note.

This would almost double the number of view modes and some view modes might conflict with the custom Paragraphs settings so .. MEH.

@thomas.frobieter is this solved in https://www.drupal.org/project/drowl_paragraphs_bs → ? Should we move this over?