Focus and reading order is not as per the visual order

[vaibhav-678]

1. In the dashboard page, drag the widgets to re-arrange their visual placement
2. Now start the tab key navigation from the top and observe the focus order is not logical. This occurs for reading order too.

Expected behaviour : Ensure that the drag and drop operation changes the widget in the DOM to maintain proper reading and focus order.
Refer to following article on examples: https://salesforce-ux.github.io/dnd-a11y-patterns/#/?_k=ndykxj
In the above given example, the widgets are moved in the DOM as well