Usability: Errors in bundles should be sorted by offset

# Why?

Currently, we don't guarantee the order in error bundles (see `runParserT'`),
That's poor UX because the author of a parser would like to see errors from left to right, in order of appearance.

# How?

- [ ] Implement sorting on NonEmptyLists
- [ ] Use it in `runParserT'` and wherever else we build bundles
- [x] Perhaps, make a function that makes bundles in `Bundle.lean` (!)

Start with runParserT' and Bundle.lean, then locate the NonEmptyList bundle construction points mentioned in the issue. Implement ordering by error offset and apply it wherever bundles are built; done means errors are consistently reported from left to right.

Written by the indexing model from the issue text.