Ej/fix persisted store

[lightlii]

Quick fix, reinstates async await syntax when getting an item from the store.

I've also made the config store consistent since zustand was stringifying the store upon save wheras by default the lib stores it as json which was resulting in configs that look like this:

{
	"experiments-flags": "{\"state\":{\"backgroundMaps\":false},\"version\":0}",
	"background-maps": "{\"state\":{\"mapStyle\":\"\"},\"version\":0}",
	"ui": "{\"state\":{\"tabIndex\":0},\"version\":0}",
	"state": {
		"maximize": false,
		"fullscreen": false,
		"defaultWidth": 1000,
		"defaultHeight": 800,
		"isMaximized": false,
		"show": false,
		"x": 2199,
		// etc.
	}
}

[ErikSin]

based on the typescript typings, it looks like get item has to return a string, and I assume createJSONStorage then just turns it back to an object...its seems like it is working.

playing around with it, I also realize that getItem, setItem, and removeItem don't need jsdoc typings, those are encapasulated it typing of the 'storage'

[ErikSin]

Can you get rid of the unnecessary typing before you merge please and thank you

[ErikSin]

with some more testing, it seems like zustand will automatically create your object into a string (so you don't need to do this typecheck)

[ErikSin]

You can just get rid of the typings for getItem, setItem, and removeItem, and then you can merge