This first geralizes the `nix` fixture with `pytest_generate_tests` to
iterate over all protocols (unless they are marked with `no_daemon`),
though for now the list of protocols is set to be empty. The lang tests
are all tagged with `no_daemon` because they are mostly pure and running
them multiple times would be wasteful.
Co-authored-by: rootile <lix@rootile.de>
Co-authored-by: piegames <git@piegames.de>
Change-Id: Ib407edb420ba4bf434cacf9563a71f5ae6fa8eef