Prepare for bindings PR, add Query.matches

[amaanq]

Closes #108
Closes #151

[jhandley]

I'm really looking forward to the query matches API. Right now I have a mess of ugliness that tries organize the captures into matches in my code.

One request would be to return a list of nodes for the match capture for patterns like ()* and ()+ that can match multiple nodes. So instead of matches() returning List[Tuple[int, List[Tuple[Node, str]]]] have it return List[Tuple[int, List[Tuple[Union[Node, List[Node]], str]]]]. This is how the Lua wrapper has implemented this API.

[jhandley]

I created this PR to illustrate what I mean. I ended up storing the captures in a dict[str, Union[Node, list[Node]]] where the key is the capture name and the value is either the single node captured or a list of all the nodes in the case of a capture in a * or + pattern. That seemed more natural than using tuples.

[jhandley]

Could this check be moved outside of the capture loop to line 2011? The result of satisfies_text_predicates() should be the same the for all captures in the match so it could be checked just once per match.

[kylebebak]

@amaanq @jhandley

Any ideas on when this might get merged? If it fixes #182 (returns captures in groups, like the Tree-sitter CLI does) it would be useful to me in building Tree-sitter integration for Sublime Text