[desk-tool] Resolve document type from template if available

[rexxars]

Given the following structure:

S.documentList()
  .title('Unspecified books list')
  .menuItems(S.documentTypeList('book').getMenuItems())
  .filter('_type == $type')
  .params({type: 'book'})

You may end up in a situation where the automatically generated editor has the schema type value *, which should be resolved by the desk tool to the correct type (structure doesn't figure out that this pane holds a specific schema type, since it's not set using schemaType(someTypeName)/documentTypeList(someTypeName).

With this PR, we use the template parameter to resolve the schema type to use if none is explicitly defined.

[thomax]

You probably need to make document available in the new resolve... function? See comment

[thomax]

Yes!