Reduce HTTP calls made to the server

This is an epic to track all improvements made to reduce the number of HTTP calls made to the server.
It is an ongoing work to make Dirve more efficient and let the server focus on others things, reducing its load. The lower the better!

Summary of HTTP calls saved for a given action (before -> after):

• Fetching a document: 2 -> 1 (NXDRIVE-986).
• Updating a DirectEdit'ed document: 3 -> 1 (NXDRIVE-1578).
• Adding a new acount: 4 -> 1 (NXDRIVE-1603).
• Creating a new folder remotely: N -> N - 1 (NXDRIVE-1636).