Feat: allow requests from same hostname to Atlas/WebAPI

[pieterlukasse]

Link to JIRA ticket if there is one: https://ctds-planx.atlassian.net/browse/VADC-1241

Improvements

• allow requests from same hostname to Atlas/WebAPI
  • example: allow gen3server.net to make calls to atlas.gen3server.net

[pieterlukasse]

closed in favor of using a frontend based .postMessage solution instead. See ticket for details.