Allow to change defaultStore in createAtom

[artalar]

We need an option defaultStore in AtomOptions. With this a user may create own createAtom implementation with own store, which useful for its customization:

// utils/store.ts
export const store = createStore({
  onPatch: console.log
})

// utils/createAtom.ts
import {createAtom as createAtomOriginal} from '@reatom/core'
export const createAtom: typeof createAtomOriginal = (deps, reducer, options) =>
  createAtomOriginal(deps, reducer, {...options, defaultStore: store})