No support for U-turn instructions

[rabidllama]

It seems that there is no support in openrouteservice for providing instructions for u-turns (see InstructionTranslator and InstructionType classes).

In the case of round trip routing (for example), it can be the case that a control point results in the route backtracking on itself:

In these cases, the instructions simply ignore the u-turn as there is not the ability to include it properly in instructions (inside the RouteResultBuilder class).

Realistically, the openrouteservice result builder should be enhanced to allow the proper use of a u-turn instruction, and in the case of the round trip it should be able to determine if there is a u-turn present without the explicit type being provided by GH. This is because GH would provide a specific via instruction (not supported by openrouteservice) and not a u-turn instruction.

[aoles]

See @TheGreatRefrigerator's forum comment for some ideas on the possible solution 🤓