ConditionsWidget.media attempted to look up media files needed for all

widgets that comprised the input for the conditions. This didn't

actually work in practice, and failed silently on template load. There

were a couple of problems, including the assumption that the default

value field for a choice was not dynamic, and that all value fields had

form widgets.
This fixes up that code, allowing media to be properly loaded for all

fields in the widget.

Tested along with some other changes that made use of widget media.

Verified that this was no longer crashing and that the media was able

to be returned for the page.