Add section for Testing User Actions

[dominiclisjak]

Help from ChatGPT :)

[darrac]

Can we cover some more tricky examples. For example, try out the 'should render toggle show more/less button' (yes, the name is weird) test in CountryFilterGroup.test.tsx in the Messe repository.

`
it.only("should render toggle show more/less button", async () => {
let showLessButton = screen.queryByRole("button", { name: /showless/i });

		expect(showLessButton).toBeNull();

		let showMoreButton = screen.queryByRole("button", { name: /showmore/i });

		await userEvent.click(showMoreButton as HTMLButtonElement);

		showMoreButton = screen.queryByRole('button', { name: /showmore/i });
		expect(showMoreButton).toBeNull();
		showLessButton = screen.queryByRole('button', { name: /showless/i });
		expect(showLessButton).toBeInstanceOf(HTMLButtonElement);
	});

`

1. It must await the user action to succeed. Why, because of something specific in that component?
2. Some other tests use fireEvent which we should probably avoid in favour of userEvent?
3. Our existing chapter suggests we use waitFor but the test I linked doesn't use it. When do we need to use waitFor if ever?

Also how does this fit in in the existing chapter. Maybe I should have told you upfront that the chapter already exist, and maybe you should have known :D

[dominiclisjak]

Updated test cases.

1. Added a chapter explaining usage of await,
2. Definitely.
3. Updated the Existing chapter.

[kamdubiel]

Done in:
#203