Add new enum Type in vehicle classification for stand-up scooters

[schmidtlorenz]

feat(vehicle classifications): add classification for stand-up scooters, motivated by possible NCAP target type

#### Reference to a related issue in the repository
refers to issue #673

Add a description

This adds a new enum Type in vehicle classification for stand-up or kickboard scooters.

Take this checklist as orientation for yourself, if this PR is ready for the Change Control Board:

• [/] My suggestion follows the style and contributors guidelines.
• [/] I have taken care about the message documentation and the fields and enums documentation.
• [/] I have done the DCO signoff.
• My changes generate no errors when passing CI tests.
• I have successfully implemented and tested my fix/feature locally.
• Appropriate reviewer(s) are assigned.

[jdsika]

Please fix build in order to hand this over to the CCB. Can you add the reference to a relevant NCAP document? Maybe even in the description. I think most descriptions would benefit from a little more verbose comments.

[ThomasNaderBMW]

Jobs are failing because of this: osi_object.proto:871:36: "osi3.MovingObject.VehicleClassification.TYPE_STANDUP_SCOOTER" uses the same enum value as "osi3.MovingObject.VehicleClassification.TYPE_SEMITRACTOR". If this is intended, set 'option allow_alias = true;' to the enum definition.

So Semitractor has already ID 16, you can take 17 e.g. @schmidtlorenz

[thomassedlmayer]

When you're using references you should comply with the contribution guidelines concerning references. The referenced websites may not be reliably available in the future. Maybe the description in line 868 alone is even enough to know what is meant?

Also, the build tests fail again because there are some additional tabs before the "//"-comment in line 870.

[schmidtlorenz]

I removed the links since I could not find persistent versions (e.g. PURL or DOI).

[pmai]

CCB 2022-12-12: Merge as-is.