MINOR: list: Add MT_LIST_DEL_SAFE_NOINIT() and MT_LIST_ADDQ_NOCHECK()

MINOR: list: Add MT_LIST_DEL_SAFE_NOINIT() and MT_LIST_ADDQ_NOCHECK()

Add two new macros, MT_LIST_DEL_SAFE_NOINIT makes sure we remove the
element from the list, without reinitializing its next and prev, and
MT_LIST_ADDQ_NOCHECK is similar to MT_LIST_ADDQ(), except it doesn't check
if the element is already in a list.
The goal is to be able to move an element from a list we're currently
parsing to another, keeping it locked in the meanwhile.