Support incidents for OSRM responses

This parses incidents on the OSRM response route leg, and splits the
incidents across the corresponding route step. Since an incident may
span multiple steps, this will duplicate an incident and adjust the
indices accordingly whenever that happens. Clients can de-duplicate
these if necessary based on the incident identifier.

android/core/src/androidTest/java/com/stadiamaps/ferrostar/core/FerrostarCoreTest.kt

@@ -122,7 +122,8 @@ class FerrostarCoreTest {
                                   triggerDistanceBeforeManeuver = 42.0)),
                       spokenInstructions = listOf(),
                       duration = 0.0,
-                      annotations = null)))
+                      annotations = null,
+                      incidents = listOf())))
 
   @Test
   fun test401UnauthorizedRouteResponse() = runTest {

apple/Sources/FerrostarCore/Mock/MockNavigationState.swift

@@ -68,7 +68,8 @@ public extension NavigationState {
                             ),
                         ],
                         spokenInstructions: [],
-                        annotations: nil
+                        annotations: nil,
+                        incidents: []
                     ),
                 ],
                 remainingWaypoints: [],

apple/Sources/FerrostarSwiftUI/TestFixtureFactory.swift

@@ -74,7 +74,8 @@ struct RouteStepFactory: TestFixtureFactory {
             instruction: "Walk west on \(roadNameBuilder(n))",
             visualInstructions: [visualInstructionBuilder(n)],
             spokenInstructions: [],
-            annotations: nil
+            annotations: nil,
+            incidents: []
         )
     }
 }