Fill in gaps in lane icon matrix

[1ec5]

#21 reorganized the lane icons to have a consistent naming scheme and layout on the PaintCode canvas. A number of slots in the grid were left without an asset, because the lane combination was either nonsensical or difficult to represent intuitively but regardless was pretty rare in the wild. The more slots we left blank, the more complicated the image selection logic became, as seen in mapbox/mapbox-navigation-ios#2809 and mapbox/mapbox-navigation-ios#2882. Though the Swift code for image selection is fantastically clever, it’s probably difficult to port over to Kotlin because the two languages are too dissimilar. Instead of relying on code-level fallbacks, the PaintCode canvas should be fully filled out with no empty slots. Then the navigation SDK can simply match the turn lane data to a literally corresponding asset, knowing that it exists.

/cc @LukasPaczos @abhishek1508 @avi-c @d-prukop @jill-cardamon

[evabishchevich]

Any progress here?

[1ec5]

#26 adds some missing assets and details a more straightforward algorithm for choosing an asset based on Directions API data.