tools/net/ynl: Add support for netlink-raw families

Refactor the ynl code to encapsulate protocol specifics into
NetlinkProtocol and GenlProtocol.

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230825122756.7603-8-donald.hunter@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>