fly cart checkout page issues on branch `feat/quick-cart-pro/issue#163`

[hz-tyfoon]

What

1. In actual checkout page changing the country/Region does change the district/state select options & the order summery dynamically. But In the current state ( d1f7e97 ) of Quick cart in branch feat/quick-cart-pro/issue#163 it doesn't.
2. Clicking the 'order now' button inside the 'cart sidebar' redirects the entire page to the 'order received'/'thank you' page. But it should load the thank you page inside the sidebar
3. Implement the design according to the design shown in the issue #163
   

Screenshots