Use SynchronousProcess::runBlocking in favor of SychronousProcess::run.
This avoid nested event loops which can produce really strange crashes
if not use carefully.

This patch only converts those processes that have a timeout of less
than 5 seconds or use the default timeout.

Change-Id: I9de8899dcc946af7049ea357a91972996c0256a1
Reviewed-by: Vikas Pachdha <vikas.pachdha@theqtcompany.com>
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>