Integrate MantleAPI v17

• Reimplement deleted Mocks that return other mocks on e.g. GetEntityRepository() in test/TestUtils.h as Fake classes
• Replace mocks with fake classes in tests
• fix wrong usage of (local) LaneIds and (global) UniqueId for lanes in LateralDistanceAction and ConvertScenarioAbsoluteTargetLaneTest
• adjust to new getter for entities (weak ptr instead of optional reference wrapper)
• entities in the repo are now shared ptr instead of unique ptrs (for tests)
• adjust to new route handling (removed AssignRoute(), add Create() in route repository and SetRoute() in entity)
• adjust to renaming of members in route definition
• adjust to redefinition of polynomial in SplineSection (struct instead of tuple)
• fix namespace for MockStatistics
• add demo as bazel target and fix compilation