chore: simplify git hooks

[bradzacher]

Closes #259

We have too many tests to run at commit time now.
I would also say that there are too many to run at push time, as well.
Our CI will run all of the tests (incl integration tests), so there's no need to force contributors to wait through a full test cycle every commit/push.

• change pre-commit hook to only run prettier.
  • commit hooks are used regularly, so we want it to be as lightweight as possible.
• add pre-push hook which runs lint + typecheck + format.
  • these are all much heavier (total i find takes ~30-40s), but I think it's good to try and block pushes because of these - some of the most common errors I see are lint problems or unformatted files.

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My question (for @JamesHenry, who I think added it?), is do we need commitizen? It's just admins that can push to master, otherwise all branch commits are hidden behind a squashed PR message (which is enforced via one of the PR status checks) - so enforcing a commit message style on the client seems unnecessary?