Add information for error handling into swagger node template

[kazuhitoyokoi]

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Proposed changes

When the node generated from swagger encounters an error (ex. HTTP 404), it throws the error and a catch node can catch the error in the current implementation. But the error event does not contain the details of the error. Therefore, it is difficult for the flow after catch node to handle the error. To solve this problem, I added information (same as http request node) for error handling into swagger node template.

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the mailing list/slack team.
• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[coveralls]

Coverage decreased (-0.2%) to 65.95% when pulling 72b0568 on kazuhitoyokoi:master-updateswaagernodetemplate into b39ecda on node-red:master.