Routing should not allow charging on on-ramps/off-ramps/slip roads

Some EV charging stations are positioned on the map close to highway on-ramps (slip roads). In these cases, the routing engine will try to have the driver charge by driving onto the ramp/slip road, which is almost always the wrong route.

See for example https://abetterrouteplanner.com/?charger_id=1188069945, which is positioned right by the eastbound on-ramp to I-22 so traffic not headed east on I-22 doesn’t get correctly routed to use the charger. Part of the problem is that the charger is incorrectly positioned in the shared data, but even so the routing engine should be smart enough to avoid using motorway/motorway_link roads as the “closest” road to a charger.