Map link in nav drawer rework

[rock3r]

Currently the "map" item in the nav drawer performs some in-app navigation before sending the users to Maps. This should be avoided as it brings them to an unpleasant white screen (even if only for a short time, in some cases). Also, the icon and label seem to suggest it's a venue map. It could be rephrased to "get to the venue" or something similar.

This is a placeholder issue to keep track of the task.