Implement is_actionable in observation

[mrkickling]

is_actionable will work like is_observable, but for steps that are able to lead to actions (being chosen).

In the TYR project for example:

• A defense step will be actionable if we have an action for it in wazuh/tyr monitor, in the same way an attack step is observable if we have an alert for it in wazuh/tyr monitor.

The idea is that this can be used to optimize training (when the agent only picks a defense that actually has an action related to it).

What needs to be done:

• [x] Update the scenario file to include is_actionable
• [x] Apply actionable to attack graph nodes .extras field
• [x] Use in observation to create a vector similar to is_observable

[kasanari]

I think adding this information to the action mask would be fine.