Show targeted package and branch for namespace in WebUI and CLI

Hey 👋,

Unless I'm missing something, it's currently a bit difficult to know which package and branch a namespace is tied to.

You can guess the targeted package by looking at the first entry in the rebuild graph and you can get the targeted branch by clicking the link to the associated CI job from the WebUI, but IMO it would be valuable to show such information directly at the top of the WebUI and in bbtw show *namespace*'s output (maybe even in bbtw list like "status date name package/branch").