Osrm-backend: Prepare list of deprecated API parameters/values for `6.0` release

[TheMarex]

We deprecated some API parameters/values over the 5.x live-cycle and need to prepare for the 6.x cleanup.

Off the top of my head the following things are marked for removal:

• [ ] StepManeuver.bearing_before and StepManeuver.bearing_after (replaced by RouteStep.intersections)
• [ ] StepManeuver.location (replaced by RouteStep.intersections)
• [ ] StepManeuver.type = "ramp" (replaced by on ramp and off ramp)
• [ ] Using bearings= without radiuses= per https://github.com/Project-OSRM/osrm-backend/issues/2983
• [ ] Specifying a bearings range per https://github.com/Project-OSRM/osrm-backend/issues/2983

Any more things that come to mind @MoKob @daniel-j-h @danpat @freenerd?

[daniel-j-h]

libosrm API:

• [ ] https://github.com/Project-OSRM/osrm-backend/pull/2941
• [ ] https://github.com/Project-OSRM/osrm-backend/pull/2991
• [ ] potentially moving away from the JSON variant

[MoKob]

• [ ] roundabout instruction -> enter roundabout + exit roundabout https://github.com/Project-OSRM/osrm-backend/issues/3108 (also deprecates rotary_name)
• [ ] direction_modifier u-turn -> invalid + new turn type u-turn https://github.com/Project-OSRM/osrm-backend/issues/3077

[TheMarex]

@MoKob can you link the tickets for those here? I'm missing some context here.

[MoKob]

Also:

• [ ] lanes should show validity per indication https://github.com/Project-OSRM/osrm-backend/issues/2935

[daniel-j-h]

• [ ] Switch from always generating hint to hints on demand https://github.com/Project-OSRM/osrm-backend/pull/3456

[karenzshea]

• [ ] Remove redundant boolean based parameter for annotations in RouteParameters https://github.com/Project-OSRM/osrm-backend/issues/3644

[freenerd]

• [ ] Remove geojson responses and go polyline only https://github.com/Project-OSRM/osrm-backend/issues/3752

[TheMarex]

• [ ] Remove --generate-edge-lookup parameter from osrm-{contract,customize} as it does nothing now

[daniel-j-h]

• [ ] In https://github.com/Project-OSRM/osrm-backend/pull/4047 I implemented an alternatives=n overload in addition to alternatives=true/false. With v6 the boolean overload should go. Needs adaption in route parameters, route parameters grammar and viaroute plugin callsite.