Trying to use an object from another pipeline should have a more obvious error message

http://stackoverflow.com/questions/43668522/unknown-producer-for-value-singletonpcollectionview

The error message says that there's an unknown producer. We can check at this point that the pipelines are the same, and if not provide a more precise error message.

Imported from Jira [BEAM-2117](https://issues.apache.org/jira/browse/BEAM-2117). Original Jira may contain additional context.
Reported by: tgroh.

Start by tracing the unknown-producer error path described in the issue and inspect where the pipeline relationship is available during that lookup. Confirm the behavior when an object comes from another pipeline, then make the completed work produce a more precise error message that identifies the pipeline mismatch.

Written by the indexing model from the issue text.