Setup UI package directories and libraries for dashboard

[shuse2]

Description

Add basic directory and library setup on the UI folder for the dashboard plugin

/ui
  index.tsx <= initializer
  app.tsx <= application top
  app.scss
  /pages <= holds smart components (only main page)
  /components <= holds dumb components
    /category1
       /component1.tsx
       /component1.module.scss
  /stores
    /actions <= defines set of actions
    /reducers <= defines set of reducers
    index.ts <= exposes store to application
  /styles <= contains scss which defines global style and constants

• It should use @reduxjs/toolkit to initialize the store

Acceptance Criteria

• When started, empty scaffolded page should be shown

Additional Information

Related Issue #6216