Make ABM infection states purely symptomatic states and provide interface to link infectivity and state transitions

[jubicker]

Motivation / Current Behaviour

Currently infectivity and infection states a pseudo-connected. The state transitions are independent of infectivity and infectivity does not depend on the infection state if an agent is infected, but it is zero for recovered (and susceptible) agents. That means that an agent's infectivity can jump from peak infectivity to zero within one hour if the agent recovers.

Enhancement description

We want to make the infection states purely symptomatic state i.e. decouple infectivity from them. The connection of state transitions and infectivity should be subject to user input by providing an interface for that as well as default implementations.

Additional context

No response

Checklist

• [X] Attached labels, especially loc:: or model:: labels.
• [X] Linked to project