fix: Update initialState type to allow for lazy initialization

[dovidweisz]

Description

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as before)

Checklist

• [x] Read the Contributing Guide
• [x] Perform a code self-review
• [x] Comment the code, particularly in hard-to-understand areas
• [x] Add documentation
• [x] Add hook's story at Storybook
• [x] Cover changes with tests
• [x] Ensure the test suite passes (yarn test)
• [x] Provide 100% tests coverage
• [x] Make sure code lints (yarn lint). Fix it with yarn lint:fix in case of failure.
• [x] Make sure types are fine (yarn lint:types).

[dovidweisz]

This fixes #2479

[dovidweisz]

Why is there no movement on this pr?

This change doesn't even change the JavaScript code it just fixes the type to reflect the truth.