Add a vss-tools recipe to build the VSS specification tools,
and recipes for the python3-anytree, python3-deprecation, and
python3-graphql-core modules it requires. The latter will be
submitted for meta-python.
Bug-AGL: SPEC-4761
Change-Id: Iffe665c0c6f168f3c37b35ce0346cad210d880c5 Signed-off-by: Scott Murray <scott.murray@konsulko.com>