Merge pull request #2298 in SNORT/snort3 from ~DAVMCPHE/snort3:host_attribute_thread_...

Merge pull request #2298 in SNORT/snort3 from ~DAVMCPHE/snort3:host_attribute_thread_safe to master

Squashed commit of the following:

commit 2806b18847f7ee0bf13cad7f4f4edbfc83b8b464
Author: davis mcpherson <davmcphe@cisco.com>
Date:   Fri Jul 24 15:42:46 2020 -0400

    stream_tcp: only perform paws validation on real packets, skip this on meta-ack packets

commit 743e235cec999c7fe1fd2017f114bcc1f0ebafa2
Author: davis mcpherson <davmcphe@cisco.com>
Date:   Fri Jul 24 12:44:35 2020 -0400

    target_based: streamline host attribute table activate and swap logic on startup and reload

commit 9fdfb1f8849320ec875a6e17976f0e4578784b0c
Author: davis mcpherson <davmcphe@cisco.com>
Date:   Fri Jun 26 14:39:01 2020 -0400

    target_based: refactor host attribute to use the LruCacheShared data store class to support thread safe access

    target_based: add mutex lock to ensure host service accesses are thread safe

    target_based: move host attribute peg counts from the process pegs to stats specific to host attribute operations"