qdoc: Reformat giant switch statement according to Qt Coding Style

This is a WS-only change to correct a lot of indentations, uses
of curly braces, and placement of else keywords. It had grown a
bit ugly.

Change-Id: Ic3c17765e3651738532653eeb653661d46bba35c
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>