ignore instructions if directions of a road are switching between explicitly <-> implicitly tagged

[karussell]

Fixes #2946. Requires graph.encoded_values: lanes.

If there is a barrier between the different directions of a road then it is usually mapped as two separate ways in OSM (and oneway) instead of a single way. But this currently leads to unnecessary instructions that we avoid with this PR:

• example 1 -> avoid "turn right"
• example 2 -> avoid "turn right"
• example 3 -> avoid "turn right" and "turn slight right" and "turn slight right"
• example 4 -> avoid "turn slight right"
• example 5 -> avoid "turn slight right"