Update logging.getLogger() calls to use edx instead of mitx

[singingwolfboy]

Part 5 of #1815

[flowerhack]

Looks good to me, so long as someone from analytics gives it a nod as well

[singingwolfboy]

@rocha Can you take a look and verify that this looks good?

[mulby]

This generally looks fine to me, my only note / concern is that somebody somewhere is configuring the 'mitx' logger and expecting those settings to be inherited by all 'mitx.*' loggers. I'm not sure what our prod logger settings look like but we should be sure to update those settings as well (if necessary).

[rocha]

LGTM 🚀

In this case, the changes are not related to analytics. It is confusing because we have been using the term tracking logs when we should be using event tracking.