Design brief
Sometimes a Pipeline can be blocked waiting for agent resources on the Jenkins server.

There are two cases when this will happen that we need to be aware of:

• Freestyle jobs - we only show the full log and agent resources are only ever blocked before the run starts. Currently we just show a generic message when this occurs.
  
• Pipeline jobs - any step in the agent may block waiting for agent resources at any time.

Common messages

• "Waiting for next available executor"
• "Waiting for next available executor on $NODE_NAME"
• "There are no nodes with the label $LABEL"
• "$NODE_NAME is offline"

Questions

• Should we we had a special rendering of the step that shows that the Pipeline is blocked from executing?
• At the moment "blocked waiting on resources* is just given the running state. Could it be useful if the developer saw a different status for this?

Scope

• Come up with a design(s) for both the Freestyle and Pipeline cases outlined above.
• Answer the questions above and lay out any design changes we will need