feat: make the encoding/decoding logic separate from core

[nitedani]

Feature idea: Make the encoding/decoding logic separate from core:

import create from "zustand";
import { querystring } from "zustand-querystring";
import urlon from "zustand-querystring/encoding/urlon";

import url from "zustand-querystring/encoding/url";
import base64 from "zustand-querystring/encoding/base64";

const useStore = create()(
  querystring(
    (set, get) => ({
      count: 0,
    }),
    {
    encoding: urlon
    // ...rest of options
    },
  ),
);