Enabling point range collector always if doc values not indexed

[jainankitk]

Description

Enabling point range collector if doc values are not indexed

Resolves #14536

[jpountz]

I'd rather not do it. My mental model is that this collector works on doc values in the default case, and can opportunistically take advantage of index statistics or points indexes when it makes things faster. So doc values should be required, and index statistics and point indexes should be optional. Plus it would be confusing to me that the same collector would work or fail dependin on the specific query impl that is used, e.g. working with a PointRangeQuery on the same field (thanks to your other PR) but not on a PointRangeQuery on another field that has the same values for every doc.