Make the site switcher work again

[brandonpayton]

Motivation for the change, related issues

The site switcher was broken by #1669. This PR is a fix for that.

Related to #1687

Implementation details

The site that is booted depends on the redux store, so the current loaded site now depends on redux state.

Testing Instructions (or ideally a Blueprint)

• CI
• Use npm run dev and manually test switching between sites

[brandonpayton]

Somehow this change seems to break opening a site with device storage, but I don't yet see how.

When using trunk, it works fine, but when using this branch, this dialog stays up, endlessly syncing:

[brandonpayton]

It seems like a playground API ref might not be updated when using device storage. Still looking into it.

[brandonpayton]

It seems like a playground API ref might not be updated when using device storage. Still looking into it.

It turned out the reason for the hanging sync UI was that we were setting the local-fs mount descriptor before syncing memfs files to OPFS which interrupted the sync.

57db51c waits until sync is complete to set the local-fs descriptor.

[brandonpayton]

I tested switching between a variety of sites with browser storage and switching between those sites and device and temporary storage.