[RFCLAT#11] remove libnetd_client_headers and netid_client.h

Removed for reducing the libaray dependency.
MARK_UNSET is going to be removed because the mark doesn't need to be an
argument of cli now. libnetd_client_headers is not required as well.

Bug: 212345928
Test: atest clatd_test
Change-Id: Ia81287dcfa2a48a89187b21d4bc721570c0d1e0f
3 files changed