We need the correct context to translate event names

Qt assumes that all strings are in the context of the class in which you
use them. So when we want to display the translated event names from
within the ProfileGraphicsView we need to make it explicit that these are
strings that come from the C part of the code.

Doing that showed another bug in the code where we foolishly compared the
translated text to a fixed string. Not smart.

Fixes #312

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>