refactor(rangeset): rewrite to use streaming algs

[sinui0]

This PR rewrites the rangeset crate with the following changes:

1. Introduction of the RangeIterator trait which is used to implement all set operations without allocations. Orienting the crate around iterators was the primary motivation for this work.
2. All operations are now proven to be correct instead of the inferior hand crafted test cases. Every set operation is exhaustively tested against the universe of sets up to a configurable size (currently set to 10).
3. Now supports no_std, because why not.
4. Replaced IndexRanges with the more flexible Index trait which can be implemented on any collection.

[sinui0]

@themighty1 @th4s now that we've released tlsn I would like to get this merged