Licensing: provider options via UI widget rather than input manually
Created by: unknwon
We currently rely on CE teammates to follow https://about.sourcegraph.com/handbook/ce/license_keys#how-to-create-a-license-key-for-a-new-prospect-or-new-customer to generate new licenses for customers/users using the following form:

The problem with current approach is that it is very easy to miss an important tag, or didn't realize old tags are deprecated and should start using the new ones.
The improvement we can make here is to create a visual form of selecting which tags to be included, on which tier (free, team, enterprise, etc.).
For example,
- Selecting "Campaigns" would automatically include the tag "campaigns" in the license.
- Selecting "Enterprise" would automatically include the tag "enterprise-0" (the latest revision) in the license.
This would help us evolve tiers and start issuing licenses under new tiers more quickly and easily.