Integrate store state with stepper navigation

[yscik]

Fixes #3135

Changes proposed in this Pull Request

• Mark steps as completed based on their actual completion
• When leaving and returning/reloading the page, pick up at the next step
• Allow to navigate back to completed steps
• Don't render until state is loaded (isFetching starts with true) - this saves a render with default data before the spinner is shown
• Move defaultRoute to QueryStringRouter - makes it a bit clearer, and saves an iteration rendering a different route

Testing instructions

• Delete the sensei_setup_wizard_data to start fresh
• Open Setup Wizard, should show Welcome step
• Complete welcome step
• Welcome step should be marked as completed
• User can navigate between Welcome and Purpose step
• Re-open Setup Wizard (without a ?step= query parameter)
• Should open Purpose step, and allow similar navigation between Welcome and Purpose steps

Not done here

• Block accessing steps not yet available by directly navigating to them, (for example, going to ?step=ready). — This adds some complexity and issues so if it's not critical we could skip/delay it. Steps not yet available are not clickable, so this is not affecting any real-world use cases.

[donnapep]

• Block accessing steps not yet available by directly navigating to them, (for example, going to ?step=ready). — This adds some complexity and issues so if it's not critical we could skip/delay it.

Agreed. This sounds like overkill.

[renatho]

Looks great! 🚀
Just a few comments about JSDoc.

It would be good in the future we take a look again in an eslint rule for that. I'll jot down here to see it at some moment.

[yscik]

Fixed JSDoc issues in 31e634c