Hack MWTemplate so it also does partial type matches

For extension-specific types such as mw: , we require that all
types be matched. But we want MWTemplateNode to match
anything with an mw:Object/Template type, even if it also has
other types (like mw:WikiLink/Category in our test case).

Hack this into MWTemplate by matching on /^mw:/ then using
a matchFunction to assert that mw:Object/Template is in the
typeof attribute.

Update the test case. Because it's now a template, there's a bunch
of store stuff involved. Remove the other test case for about
group forcing because it's now a duplicate of this one.

Change-Id: Iacbe952a66d610c19b46bd76b84c50488857ac29
Merge "Hack MWTemplate so it also does partial type matches"