Move anonymous Weight implementation in PointRangeQuery to named class

### Description

The `Weight` implementation in `PointRangeQuery#createWeight` is anonymous class making it difficult to extend or reuse specific logic from the class. Not to mention the class being more ~400 lines of code which makes good case for named class anyways IMO.

Start at PointRangeQuery#createWeight and inspect the anonymous Weight implementation, which is described as roughly 400 lines and contains the logic to reuse. Extract it into a named class while preserving the current behavior, then run the existing tests covering PointRangeQuery to confirm the refactor is complete.

Written by the indexing model from the issue text.