Add site/language conditions for feedback button

Only show the survey button if the user's language matches and the site is
enabled, and log which site we are on.

The corresponding site configuration commit is
Ic07432649906890785769ce5127761e2c84316e2

Change-Id: I575bb286f4289489b80505c901f5a9e7aeecec8b
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/261