Include Tekton Bundle URL in resource version object

[lcarva]

Feature request

Tekton Tasks from the tektoncd/catalog are packaged as Tekton Bundles available at gcr.io/tekton-releases/catalog/upstream/<task-name>:<task-version>.

Let's include this information in the Tekton Hub API responses whenever the response includes the object representing a certain task version.

Use case

As a developer, I would like to programmatically check if a newer version of the Tekton Bundles I use are available without having to hard-code a particular registry or a special convention.

Ideally, the URL would also include a digest reference, e.g. gcr.io/tekton-releases/catalog/upstream/buildah:0.4@sha256:dc4ab79388521db81ee3f966d63196be12528ebaf8e4a0a00b54384eacaf72ec

[lcarva]

Although tektoncd/catalog only publishes bundles for tasks, that's a property of that catalog. It would be ideal to also include the Tekton Bundle URL for pipeline resources.

[lcarva]

Given the decision to move away from Tekton Hub (#667), and the lack of interest, let's just close this out.