Test: add enable rule so that step always do something (equivalent, but more in the spirit of the model)

Depending on the kind of network, we should raise an exception. Indeed
such information should not be available in anonymous networks.

We will add such checks later.

instead of duplicating its content

Actually, I've just realized that the I/O mode of rdbg already makes
it possible to use sasa from rdbg (exit event only). This plugin would
only be necessary when we would need a finer grained intrumentation, e.g.,
to stop at enable step, or to at each process call/exit.

with
- a git 1.0.0 tag
- a GITLAB_AUTH_TOKEN set in the CI/CD settings

This is necessary to be able to use sasa with luciole.  Indeed, in
rdbg/lurette, luciole always plays first. Hence if we want sasa to
play after luciole, we can use the option.

Note that from the lurette point of view, sasa plays the role of the env
as it needs to start playing, to provide Lutin the enable values for
the first demon step.

with algo several actions, and allow lurette to chose them.

and reuse it for Neighbor, which make the naming more consistent.

In conjunction with -rif, that change makes it possible to use sasa with lurette!

todo: where several actions are enabled in a process, one is chosen at random
at the sasa level (whereas it should be possible at the lutin level).

Also add the list of neighbors to the init function. The rationale is that
to give a sensible initial value to local vars of type 'Neighbor', we need
the neighbors number.

I could have chosen to pass an integer only. Well, who can the plus
can the minus.