Consolidate duplicate tc-loader scripts

[tohojo]

We should probably consolidate the different copies of the TC loader scripts in subdirectories into a single version in a parent/lib directory...

[simosund]

Same thing probably goes for the configure script to detect if iproute has libbpf support.

[tohojo]

Yeah. IIRC, @netoptimizer expressed a preference for keeping separate configure scripts in each subdir, but they can still share code :)

[simosund]

Worth mentioning that in my current PR I've extended the tc loader script somewhat to support attaching a pinned program (and gotten rid of the configure script).

[netoptimizer]

As libbpf now support TC-attaching directly, we should consider converting "pping" and "traffic-pacing-edt" to use that instead of mentioned shell script.

[simosund]

Yep, converting pping to use libbpf for attaching the tc program is on my TODO list, so this issue is likely goning to resolve itself that way.