Select Index instead of document with All/Any support

[MichaelPetrinolis]

As mentioned in #467 and #422, there are times that we need to query an index to retrieve some values, but the documents should be filtered with multiple indexes. Unfortunately this can't be done now, as the IQuery returns documents (a large payload, which must be materialized in memory to read the specific info) or use the IQueryIndex but without support for All/Any.

A solution is to introduce a ForAdvancedIndex() method to IQuery, which would select from the Index table joined with the document table. The method should return an IQuery instance, where then all the other methods work as the simple For method. The method will only allow to select from Map Indexes.