Improve handling push notification clicks

Right now, when a push notification is clicked we only:

1. Open messages tab if it's a message notification.
2. Open notifications tab otherwise.

With the new Airnotifier version we receive more data from Moodle, so we can improve this and open the right page in the app.

This is the list of notifications which handling should be improved (by order and if we receive enough information from teh site):

• Forum: Subscribed forum posts
• Message: Instant message
• Message: Contact requests notification
• Assignment: Submission updated (notify grader)
• Feedback: User completed
• Badge: recipient notification
• Enrol: notify expiration to enrolleD user (manual/self)