feat: create require-hook rule

[G-Rath]

tbh this was a bit of a no-brainer to have as a rule - the more I think about it and check my existing tests, the more I think "yeah there's no reason that can't/shouldn't be wrapped in a before hook" 😅

The docs should explain the important stuff - namely, that this rule flags pretty much all common "action" statements like re-assignments and function calls that are not within a hook.

I have excluded function calls on the jest global, like jest.mock but suspect some of those should actually also always be within a hook function?

I also think we should probably make this a recommended rule, but understand if you don't want to delay the new major any further.

Closes #752

[G-Rath]

I'm wondering if this rule should have a strict or loose option (depending on what we want as the default) to adjust how it handles cases like:

const myValue = getValue();

describe('some tests', () => {
  ...
});

For the above you could argue that myValue should be a let that gets assigned in a beforeEach, based on it being assigned the return from a function call (vs if it was a primitive literal, in which case it is fine).

But I wouldn't be surprised if some folks found it too noisy, due to having builder functions that are returning static values? 🤔

[SimenB]

I like it!

[github-actions]

🎉 This PR is included in version 24.7.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[github-actions]

🎉 This PR is included in version 25.0.0-next.6 🎉

The release is available on:

• npm package (@next dist-tag)
• GitHub release

Your semantic-release bot 📦🚀