Removed static versions of MatchAllDocsQuery

If a static cached version of MatchAllDocsQuery is used through for
instanst the `query_string` together with a boost like `*:*^2.0` the
globally used version is modified since queries are not immutable and it's
boost variable can change at any time. Holding on to queries that are modifiable
is risky and should not be done in a global scope.
This commit also adds tests for constant scores from `constant_score` query.

Closes #3521