RFC 167: Generate new licenses with versioned tags

Created by: unknwon

We should start to be able to generate new licenses with new versioned tags on Sourcegraph Cloud for sales team to use.

Some of the work has been done in this branch: https://github.com/sourcegraph/sourcegraph/compare/jc/enforce-product-tiers (i.e. define the new tags).

Part of RFC 167.