Getting rid of mapdirective controller

It doesn't make sense to have a mapdirective specific controller in order for the contextmenu directive to work properly.

This PR removes the specific controller and removes the require`require: '^gaMap'` from the context menu directive and thus renders the components more independant. The contextmenu directive is now configured like we configure all other directives.

I'd like for the original authors of mapdirective and contextmenu directive to review this as I'm maybe missing the point of the `require: '^gaMap'` and `GaMapDirectiveController`