feat: accept beforeRetry hook

[jembezmamy]

This MR introduces beforeRetry hook in the setup function:

const setup = require('qunit-retry');

const retry = setup(QUnit.test, { beforeRetry: () => resetEnvironment() });

It allows performing custom reset logic (e.g. recreating Sinon sanbox) between retries.

⚠️ This MR changes the setup function signature which currently expects maxRuns as a second argument. This MR uses an options object instead. This change was not published on NPM yet, so I think there is no risk in introducing this breaking change.