Introduce a new `fingerprint` field to `TextSummary`

This is calculated in `Rope` and uses the `bromberg_sl2` homomorphic
hash function to determine the fingerprint of a single chunk and
compose each chunk fingerprint into a single fingerprint for the entire
rope that is equivalent to hashing all the rope's bytes at once.
c31a233aadAntonio Scandurra committed on 6/17/2022, 10:12:37 AMparentcef85f5
6 files changedLine totals unavailable