TestHelper should not depend on MapboxNavigation

[1ec5]

TestHelper depends on MapboxNavigation, which has some awkward consequences with SPM:

• MapboxCoreNavigationTests ends up depending on MapboxNavigation, which forces us to disable large swaths of MapboxCoreNavigationTests: #2792.
• Bench depends on both MapboxNavigation and TestHelper, which also depends on MapboxNavigation. A static framework can’t be linked twice like that.

We should remove TestHelper’s dependency on MapboxNavigation. The only thing that requires MapboxNavigation is Plotter, so perhaps we could change it to plot routes on a static map using MapboxStatic.swift.

/cc @mapbox/navigation-ios

[1ec5]

First step is to replace usage of RoutePlotter in RouteControllerSnapshotTests and SimulationLocationManagerTests with a simple check that the route has the right coordinates. Then the only usage of RoutePlotter is in ManeuverArrowTests, which is part of MapboxNavigationTests, so we can move NavigationPlotter.swift from the TestHelper target to the MapboxNavigationTests target and remove TestHelper’s dependency on MapboxNavigation (and the map SDK).

[1ec5]

Fixed in mapbox/mapbox-navigation-ios#2861.