tracing/user_events: Add ABI self-test

Add ABI specific self-test to ensure enablements work in various
scenarios such as fork, VM_CLONE, and basic event enable/disable.
Ensure ABI contracts/limits are also being upheld, such as bit limits
and data size limits.

Link: https://lkml.kernel.org/r/20230328235219.203-8-beaub@linux.microsoft.com

Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>