Re-implement manchester parser without `instaparse`

[inaimathi]

Profiling is pointing to instaparse as the main performance bottleneck. We should re-implement the existing insta grammars using regexes/string slicing directly (there are a lot of assumptions we can make about our input because of the way we're processing it).

This task is for the manchester parser specifically. This is a lower priority for various reasons(

• The manchester parser is incomplete
• manchester expressions are isolated from the main grammar
• manchester expressions are expected to be relatively small

), but should still probably be done at some point.

[jamesaoverton]

The Manchester syntax is complex, recursive, and variable enough that it probably makes sense to keep using a parser library for it. Manchester expressions form a small part of most ontologies, so the perfomance hit should be small.