search: introduce fallback parser for dangling parens

Created by: rvantonder

Stacked on #9761.

Introduces a fallback parser that may as well be called the honey badger parser because it just doesn't care. This parser is triggered after all other parses and heuristics fail. The parser doesn't give any significance to parentheses, so if they're dangling or partially balanced doesn't matter, it all just becomes a pattern. That means you can search things like

main( or foo( and it'll be interpreted as "main(" or "foo("

See tests for more examples.