Introduce Program::attach_iter_with_opts()

[d-e-s-o]

Add the Program::attach_iter_with_opts() method to allow for iterator attachment with support for providing additional options.

[d-e-s-o]

And I see that bpf_iter_link_info is a union, so we probably want to model that a tad differently then.

[tyrone-wu]

Heyo o/

This was how I ended up implementing the iter variants when I implemented link_info in aya.
https://github.com/tyrone-wu/aya/blob/aya/link-info/aya/src/links/info.rs#L118

It's kind old code (about a yearish ago) that I ended up not having the time & energy to get merged to upstream aya, and probly won't get around to since i'm kinda moving away from aya. 🫠 so it's been sitting in limbo ever since.

If it's still the same today, the .target_name should map to the bpf_iter_link_info variants:

• "bpf_map_elem" | "bpf_sk_storage_map" to map
• "cgroup" to cgroup
• "task" | "task_file" | "task_vma" to task