Fix service_node URL handling and redirect treenode to service_node
Fix service_node URL handling and redirect treenode to service_node

Fixes two problems.

1. All unit?service_node=N URLs were broken
2. All leagacy unit?treenode=N URLs were not redirected
   to the correct URL

City-of-Helsinki/servicemap,City-of-Helsinki/servicemap,City-of-Helsinki/servicemap