Merge pull request #2017 in SNORT/snort3 from ~SUNIMUKH/snort3:drop_servicability...

Merge pull request #2017 in SNORT/snort3 from ~SUNIMUKH/snort3:drop_servicability to master

Squashed commit of the following:

commit 38e5c894583a168c71633f6fd427a9b349775b01
Author: Sunirmal Mukherjee <sunimukh@cisco.com>
Date:   Fri May 29 05:06:55 2020 -0400

    active: add drop reason and ability to publish mapped drop reason ID to
    	the DAQ layer

        Drop/verdict reason handling has been moved from PacketTracer to Active.
        Many modules have been changed to update the drop reason when deciding
        to drop. The Active API has been extended to allow external modules to
        map reason strings to verdict reason IDs to be sent to the DAQ layer.