Mark v2 context as "do not use", consider duplicating v1 context to v3 to avoid confusion

[dlongley]

The vocab base URL should be: https://w3id.org/vc-barcodes#:

https://w3id.org/vc-barcodes/v1 => https://github.com/w3c-ccg/vc-barcodes/blob/main/contexts/vc-barcodes-v1.jsonld

See spec: https://w3c-ccg.github.io/vc-barcodes/

The VDL examples in the vc-barcode specs need to be updated to use a new context once produced here. I also recommend using the /v3rc1 format for the v3 context (appending rcX until we reach spec stability in a standard group).

[dlongley]

It looks like the plan here is that the vdl/v2 context should be deprecated / marked "do not use" and the v1 context should be used instead. The v2 context erroneously added some terms that are defined elsewhere and can be brought in via the vc-barcodes/v1 context, so there is no need for them in the vdl context.

I think we should probably put out a v3 context anyway, so anyone looking for the latest version will get the right things.