Add support for Workflows when loading comment files

[nosmo]

When a job is initiated via the pipeline plugin, the Run object is no longer an instance of Build, it becomes an instance of WorkflowRun. This means that the current logic for finding comment files on remote workers does not find the comment file when using a pipeline. Additionally, WorkflowRuns are more complex objects and they can have multiple associated workspaces.

This PR introduces support for finding the files on the remote workspaces.

This change does not allow for seamless discovery of the files in workspaces if multiple nodes are used, and users will be required to stash and unstash as is appropriate if using remote nodes, but I've included a documentation note to explain this.

(This is a repost of #682 - I was requested to re-file)

[Kentalot]

looks like the same result :( Did you merge master into your branch? maybe the most recent merges don't play nice with your branch?

[nosmo]

Looks like a rebase against master fixed it - not entirely sure why as tests look the same locally.

[Kentalot]

Yay! @samrocketman looks like this one can be approved and merged. Tests seem fixed!

[samrocketman]

@nosmo seems the git author for your commits is off. Do you need to update the author? Otherwise your GitHub account would not be counted among the contributors.

[nosmo]

@samrocketman good catch - I've changed the author in commits.

[Kentalot]

now failed again haha

[nosmo]

Rebased and ran again, looks like they're passing.

[redwyre]

Any updates on this?

[pkazi]

Any update on this? Not able to use Comment file feature for Pipeline jobs which runs on slave nodes.

[fr-kqkq]

Any update on this?

[TheSAS]

Any updates?