Name image fields from fieldsets are rendered differently from main schema

[datakurre]

In DexterityFieldTile there's special display template registration for NamedImageWidget, but it only matches for the fields on content type's main schema.

Two possible fixes:

• Just get rid of the special template and figure out a better solution for fields with images

• Stamp form groups (fieldsets) with some marker interface to be able to register custom template also fro those