Show nearby routes

Summary:
Task: https://phabricator.kde.org/T5036
Related Google Code-In 2017 task:
https://codein.withgoogle.com/dashboard/task-instances/4841193496117248/

Reviewers: rahn, nienhueser

Subscribers: nienhueser, rahn

Differential Revision: https://phabricator.kde.org/D4073