Pipelines need to be marked as disabled when disabled

Design brief
A pipeline can be disabled to prevent its automatic execution. This commonly happens when pipelines are broken so that they do not execute and use valuable agent resources to execute. They are not deleted as the author plans to resurrect them.

Scope

• Add API to check if Pipeline is enabled or disabled
• SSE events for Pipeline is enabled or disabled
• Show and hide the disabled state of the pipeline based on the API and SSE event.