[FEATURE] Creating the executor for MADQN

[nima-siboni]

Feature

As the first step to have the first MADQN system, the executor is created.

Proposal

The MAPPO design in jax/systems/mappo and its executor are modified for which :

• FeedforwardExecutorSelectAction is changed to FeedforwardExecutorSelectActionValueBased
• PPONetworks is changed to DQNNetworks
• EpsilonScheduler is added

Testing

Tests are same as MAPPO system_tests with additional tests:

• steps_counter
• epsilon scheduler

Definition of done

A precise outline for the feature to be considered fully implemented, i.e. done/complete. The executor is implemented and passes the tests.

Mandatory checklist before making a PR

• [ ] The success criteria laid down in “Definition of done” are met.
• [ ] Code is documented - docstrings for methods and classes, static types for arguments.
• [ ] Code is tested - unit, integration and/or functional tests are added.
• [ ] Documentation is updated - README, CONTRIBUTING, or other documentation.
• [ ] All functional tests are green.
• [ ] Link experiment/benchmarking after implementation (optional).

Links / references / screenshots