net-shapers: implement NL set and delete operations

net-shapers: implement NL set and delete operations

Both NL operations directly map on the homonymous device shaper
callbacks, update accordingly the shapers cache and are serialized
via a per device lock.
Implement the cache modification helpers to additionally deal with
NODE scope shaper. That will be needed by the group() operation
implemented in the next patch.
The delete implementation is partial: does not handle NODE scope
shaper yet. Such support will require infrastructure from
the next patch and will be implemented later in the series.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/1e6a34a4095b35d773d2b9c476164671bbcf8397.1728460186.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>