Horizontally align labels on info widget page.

Left aligning text values looked wrong.

Use Qobject cast to filter labels from any other qobjects around and
set alignment. Doing this via Qt Designer would be tedious.

Signed-off-by: Amit Chaudhuri <amit.k.chaudhuri@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>