Add support for SB3 callbacks in adversarial training

[smanolloff]

Description

Support for stable_baselines3 style callbacks in adversarial training.

This feature was partly addressed in #626, but the author seems to have lost interest there

Testing

Tests in tests/algorithms/test_adversarial.py

[smanolloff]

the master branch apparently is unstable so the failing tests are unrelated to this PR