[Feature]: support test.fail.only

[vitalets]

🚀 Feature Request

Support test.fail.only() to be able to focus on failing test.

Example

Imagine I have two tests and 1st is expected to fail:

test.fail('my test', async ({ page }) => {
  throw new Error('foo')
});

test('my test 2', async ({ page }) => {
  // pass
});

If for some reason 1st test does not fail, I'd like to focus on it with adding .only to the test function. But nether of the following works:

test.fail.only('my test', async ({ page }) => { ... }
test.only.fail('my test', async ({ page }) => { ... }

Error:

TypeError: test.fail.only is not a function

Note: If I use test.fail() inside test body, it works:

test.only('my test', async ({ page }) => {
  test.fail();
  throw new Error('foo')
});

Motivation

I'd like to be able to focus on expectedly-failing tests as well as I can on passing tests.