Revert "test/libalias: Tests for instantiation and outgoing NAT"

11-STABLE to too different. libalias misses to many patches to keep
in touch with the planned improvement. Even the tests infrastructure
needs adjustments to prevent build (install) failures.

This reverts commit b4b99d2333faeb6ba383dcabde5d0e4c90cf23de.

Git Hash: 1d2ac87f1f8596b2b2ac08cd9e715e5278f27486
Git Author: donner@FreeBSD.org

test/libalias: Tests for instantiation and outgoing NAT

In order to modify libalias for performance, the existing
functionality must not change. Enforce this.

Testing LibAliasOut functionality. This concentrates the typical use
case of initiating data transfers from the inside. Provide a
exhaustive test for the data structure in order to check for
performance improvements.

In order to compare upcoming changes for their effectivness, measure
performance by counting opertions and the runtime of each operation
over the time. Accumulate all tests in a single instance, so make it
complicated over the time. If you wait long enough, you will notice
the expiry of old flows.

Reviewed by: kp
Differential Revision: https://reviews.freebsd.org/D30307
Differential Revision: https://reviews.freebsd.org/D30335
Differential Revision: https://reviews.freebsd.org/D30379

(cherry picked from commit 7fd8baee756efa18b6bbb17cbf3a652eb2058d87)
(cherry picked from commit c1fbb54f4b100d576da7ab065d1887a21f691936)
(cherry picked from commit 33c1bdfc3e098862100bab7a8dc729d8c78ffa7c)

Git Hash: b4b99d2333faeb6ba383dcabde5d0e4c90cf23de
Git Author: donner@FreeBSD.org