Update storage based on URLs instead of TabIds

[phenixcoder]

Currently the data flag storage is mapped using windowId and tabId.

Instead of this it should be based on URL like :

1. hostname for Hostname with port and http scheme
2. hostname+path for path also.

While setup, the app should specify which value should be used to map data.

{
   root: 'hostname',  // or 'hostname+path'
}