Functional API's setup should accept Promises in getStoredClient

[mrcnk]

Current implementation of setup only accepts sync getters for getStoredClient. To make a better DX with Chrome extensions we should refactor setup to accept Promise<string> as a part of chrome.storage.local.

[mrcnk]

Current workaround if using async storages (like Chrome storage or React Native storage):
Get the persisted client state (as serialized string) in async function and pass it to the setup as:

async onSubmit(values) {
    const client = (await AsyncStorage.getItem("storedClient"))?.toString() ?? "";
    const paired = await setup({
        deviceId: values.deviceId,
        password: values.password,
        name: "Wallet",
        getStoredClient: () => client,
        setStoredClient,
    });
}