Issue #2947739 by Jaypan: Refactoring JS, separating three different integration types into separate scripts, so that they are only loaded if/when they are needed

Issue #2947739 by Jaypan: Ensuring that the nodejs room is changed when the user changes threads. Adding comments to code

Issue #2947739 by Jaypan: Spun out Nodejs connection URL to configuration, configurable on the private message settings page