[views/templates] provide a modal main template (closes #3274672)
The current NonTemplatableViewTemplate may seem to provide the desired
feature if a '__notemplate' is provided in the form, unfortunately,
it:
* wraps the view in a spurious div
* calls view.set_stream(), which has the effect of wiping any js/css
resource recorded until then by the view, leading to hard-to-track
missing resources symptoms
if 'same_as' in schema:
sync_schema_props_perms('same_as', syncperms=False)
sync_schema_props_perms('Bookmark', syncperms=False)