* perf: use a priority-queue-based search for updating text
It tends to produce diffs with more continuous edits,
which is more efficient when we need to apply them to CRDTs
* fix: use better text diff calc
* refactor: add text update options struct
* chore: update text.update comments
* chore: fix warnings
* fix: rm a dumb optimization
* refactor: Loro import function should return LoroEncodeError
- Change return type
- Add support for handling potential errors:
- Invalid or non-existent frontiers
- Exporting old snapshot format from trimmed snapshot doc
- Improve compatibility with trimmed docs
* fix: add tests and fix a few places that need to return err
