[@mantine/hooks] use-timeout: Memoize clear and start functions

[lgaspari]

Solves #3789

1. Wrap both clear() and start() functions with the useCallback() hook so that they won't change across re-renders (unless they have to, e.g. start() depends on delay).
2. Add missing test case for autoInvoke effect when delay changes.
3. Correct autoInvoke effect dependencies to include clear() and start() as well as options.autoInvoke.

As far as I could check, the above changes shouldn't affect anyone using this hook. However, there's a separate commit (see point 3) that changes autoInvoke effect dependencies and I'm not 100% sure of relying on options.autoInvoke. People shouldn't really change that setting after the first render, so I'd think it's safe, but I'm open to suggestions.

[rtivital]

Thanks!