feat!: add promise-based return assertions, do not auto-resolve returned promises

[sheremet-va]

Description

Fixes #5747
Fixes #5647

This PR removes auto-awaiting of mock.results[0].value. To make the migration easier, we are introducing several new assertions mimicking toHaveReturned*:

interface Assertions {
  toHaveResolved: () => void
  toHaveResolvedTimes: (times: number) => void
  toHaveResolvedWith: <E>(expected: E) => void
  toHaveLastResolvedWith: <E>(value: E) => void
  toHaveNthResolvedWith: <E>(nthCall: number, value: E) => void
}

I did not add simple variations (toBeResolved and so on) because they are supposed to be softly deprecated.

You can also still get resolved results in mock.settledResults[0].value:

const mock = vi.fn(() => Promise.resolve(1))
- const result = mock.results[0].value
+ const result = mock.settledResults[0].value

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• It's really useful if your PR references an issue where it is discussed ahead of time. If the feature is substantial or introduces breaking changes without a discussion, PR might be closed.
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Tests

• Run the tests with pnpm test:ci.

Documentation

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Changesets

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