Add pre-commit hooks in the rust template.

[daemontus]

It can be argued that it is useful to never commit invalid code. Or sometimes you just forget to run tests and when it hits CI its too late... This PR adds git pre-commit hook to the rust lib template that will run cargo formatting and test checks before every commit, ensuring we never unintentionally commit broken code.

Hooks need to be enabled on every machine using git config core.hooksPath .githooks