Also ensure cleanup runs in HParseResult test

- Also, added a note explaining the difference in HBytes' implementation

- Also add hammer-parse-apply to readme

- HDoParseRetBreakpoint wasn't calling top_level_parse.return_from_h_do_parse()
- Fixed KeyError in return_from_h_do_parse()
- Print parser stack and input preview after apply, as with hammer-parse-step

Printing failed when stopped in h_do_parse with a parser whose type hasn't been resolved yet

- Stops when the HParsedToken is returned
- prints AST
- attempts to continue to the next h_do_parse invocation