bonding lacp: replace slave string with member

- Replace textual string slave with member except APIs.
- For APIs, mark the existing APIs as deprecated and introduce new APIs
- While introducing sw_bond_interface_dump, add the optional filter by
  sw_if_index and enhance the testcases to make use of it.

Type: improvement

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: Ib6626c514e45350308aeeda0decb70f3aba2f63e