Utility of lane_number: time to deprecate?

[j-d-b]

The optional lane_number property on the Lane object was left in the major v3.0 release as there were reservations about giving a lane with a not typically driveable lane type (e.g. shoulder or sidewalk) a number. For clarity and to remove connection to what individuals think of when they see "lane number", the required lane order property was added. order is used as an index to identify the lanes positions (order) relative to each other. For many contributors/producers, this was the utility of lane_number, so with order, lane_number has no value. I support that conclusion and think that lane_number remaining in the spec just adds confusion.

In summary, it is not clear that there is any utility in lane_number.

If there are any producers or consumers who see value in lane_number aside from identifying the lane's position, please raise your opinions!

If there is no value, the next step is to deprecate lane_number.

[j-d-b]

Every time I present the spec, I always gloss over lane_number as for new adopters it adds confusion rather than value.

Seeing again no new comments here, I'll move forward with the PR.

[natedeshmukhtowery]

Thumbs up.

[j-d-b]

Completed in #175.