tests: Add ktrace capability violation test cases

tests: Add ktrace capability violation test cases

Introduce regression tests for ktrace(2) that target capability
violations.

These test cases ensure that ktrace(2) records these violations:
- CAPFAIL_NOTCAPABLE
- CAPFAIL_INCREASE
- CAPFAIL_SYSCALL
- CAPFAIL_SIGNAL
- CAPFAIL_PROTO
- CAPFAIL_SOCKADDR
- CAPFAIL_NAMEI
- CAPFAIL_CPUSET

A portion of these test cases create processes that do NOT enter
capability mode, but raise violations. This is intended behavior.
Users may run `ktrace -t p` on non-Capsicumized programs to detect
violations that would occur if the process were in capability mode.

Reviewed by:	markj
Approved by:	markj (mentor)
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D40682