[SSC-395] XDP filter for bypassed traffic

[scott-kiester]

This PR includes the initial implementation of the XDP stream filter, which will drop traffic that has been bypassed by Suricata.

Once a flow hits a bypass rule in Suricata, it's added to "flow_table_v4", which is an ebpf table that allows flows to be looked up by tuple. The XDP stream filter checks the table when it gets new traffic; if the flow matches, then the traffic is dropped, which saves CPU cycles.

The XDP stream filter currently only works with mirroring deployments. Support for internal tap will be added later. An HLD is needed for that work.

Related PRs:
Add the stream filter to the build (awn)

Testing has been performed on both virtual and physical sensors.

There are no plans to merge these changes back to the OSIF Suricata repo.

Make sure these boxes are signed before submitting your Pull Request -- thank you.

• I have read the contributing guide lines at
  https://docs.suricata.io/en/latest/devguide/contributing/contribution-process.html
• I have signed the Open Information Security Foundation contribution agreement at
  https://suricata.io/about/contribution-agreement/ (note: this is only required once)
• I have updated the user guide (in doc/userguide/) to reflect the changes made (if applicable)

Link to redmine ticket:

Describe changes:

Provide values to any of the below to override the defaults.

To use a pull request use a branch name like pr/N where N is the
pull request number.

Alternatively, SV_BRANCH may also be a link to an
OISF/suricata-verify pull-request.

SV_REPO=
SV_BRANCH=
SU_REPO=
SU_BRANCH=
LIBHTP_REPO=
LIBHTP_BRANCH=

[rahim-rani]

not equal to 1 so it breaks if too many args are supplied

[rahim-rani]

else can be removed