match-only query support (terms,wildcards,ranges) for docvalues fields.

Historically, you had to invert fields (indexed=true) to do any queries against them.

But now its possible to build a forward index for the field (docValues=true).
I think in many cases (e.g. a string field you only sort and match on), its unnecessary and wasteful
to force the user to also invert if they don't need scoring.

So I think solr should support match-only semantics in this case for term,wildcard,range,etc.