working unit test for HttpNotificationStrategy
a smaller version of the HTTPClient fixes for NMS-7122
NMS-7122 partial - fix RT to use HTTPClient properly

This is a minimal version of the full patch for NMS-7122 that just fixes
RequestTracker integraiton, as I just don't trust changing everything
right before release.

The full version will get merged to develop for 15.0.

Merge remote-tracking branch 'origin/jira/NMS-7122-minimal' into rc/stable/1.14.0