map: separate name, route source logic

map: separate name, route source logic

Summary:
 - So far, elm_map only provides Open Street Map
   and lacks ability to expand to other map providers
   since it's xml parse only fits into that of OSM.
 - This patch is to make route and name source same to
   tile source, which supports other map tile providers.

Reviewers: woohyun, cedric

Reviewed By: cedric

Subscribers: cedric

Differential Revision: https://phab.enlightenment.org/D3303

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>