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]

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