Suggestion hex offset(limit) support for head/tail binary mode

[Grigoriy Sokolik]

Dear core os maintainers community!

Now I'm working a lot with binary data (gRPC traffic), and I found `tail
-c` / `head -c` / `hexdump -C` extremely useful. The only thing is that I
have to count offsets (limits) for tail/head manually each time relying on
hexdump's markers which are in hex numbers. It would be nice to support
something like, for instance, `tail -c +0x1a my_binary_dump.bin`. I even
could try to implement this feature myself, but first I want to get
approvals and advice from the community.

Thanks!
Best regards,
Grigorii