Rewrite ftrace tests into new (C) API

[pevik]

Ftrace tests should be review if they are still relevant and rewritten. Ideally into new C API, or at least into new shell API.

https://github.com/linux-test-project/ltp/tree/master/testcases/kernel/tracing/ftrace_test/

ftrace_regression01.sh test is somehow outdated as on 6.18.1:

ftrace_regression01 1 TPASS: Finished running the test
/opt/ltp/testcases/bin/ftrace_lib.sh: line 128: echo: write error: Invalid argument

On other sles 6.12 based kernel it also does not check path existence, it should probably TCONF:

cat: /sys/kernel/debug//tracing/events/kmem/mm_kernel_pagefault/enable: No such file or directory
/opt/ltp/testcases/bin/ftrace_regression01.sh: line 68: /sys/kernel/debug//tracing/events/kmem/mm_kernel_pagefault/enable: No such file or directory
/opt/ltp/testcases/bin/ftrace_regression01.sh: line 75: /sys/kernel/debug//tracing/events/kmem/mm_kernel_pagefault/enable: No such file or directory
ftrace_regression01 1 TPASS: Finished running the test
/opt/ltp/testcases/bin/ftrace_lib.sh: line 128: echo: write error: Invalid argument
### TEST ftrace_regression01 COMPLETE >>> 0.