ODC/Pipelines TektonHub Improvements

Problem:

Recently we integrated TektonHub integration into the pipeline builder in ODC. This presents us with two new problems: (1) there's no way for admins to "shut off" integration with TektonHub integration in the Pipeline Builder (2) TektonHub tasks are being shown which are not supported by the cluster

Goal:

1. Admins should be able to shut off integration with Tekton Hub
2. Developers should only be shown tasks which are supported by the cluster

Acceptance criteria:

1. Admins should be able to opt out of Tekton Hub integration
2. As a developer on a cluster where Tekton Hub integration has been turned off, I should only be able to see ClusterTasks and Tasks which are in the current namespace
3. As a developer, I should only be able to see tasks from Tekton Hub which are supported by the cluster.
4. As a developer, when looking at the details of a task, I would like a link to jump out to more docs for the task.

Dependencies (External/Internal):

For AC #4, we may need API support. Note here: it would be nice to have the link as documentationUrl or something, so that even if the user has hosted tektonhub, we could get the link through API rather than manually forming it

Design Artifacts:

• Use our current convention of customizing the Developer Experience.
• There should be no manual intervention need to hide tasks which are not supported by the cluster. This should be handled automatically.

Note:

In the future we will allow admins to opt in to use a local Tekton Hub