Big refactor - SB3 upgrade - Last before v1.0

Breaking Changes

• Removed LinearNormalActionNoise
• Evaluation is now deterministic by default, except for Atari games
• sb3_contrib is now required
• TimeFeatureWrapper was moved to the contrib repo
• Replaced old plot_train.py script with updated plot_training_success.py
• Renamed n_episodes_rollout to train_freq tuple to match latest version of SB3

New Features

• Added option to choose which VecEnv class to use for multiprocessing
• Added hyperparameter optimization support for TQC
• Added support for QR-DQN from SB3 contrib

Bug fixes

• Improved detection of Atari games
• Fix potential bug in plotting script when there is not enough timesteps
• Fixed a bug when using HER + DQN/TQC for hyperparam optimization

Documentation

• Improved documentation (@cboettig)

Other

• Refactored train script, now uses a ExperimentManager class
• Replaced make_env with SB3 built-in make_vec_env
• Add more type hints (utils/utils.py done)
• Use f-strings when possible
• Changed PPO atari hyperparameters (removed vf clipping)
• Changed A2C atari hyperparameters (eps value of the optimizer)
• Updated benchmark script
• Updated hyperparameter optim search space (commented gSDE for A2C/PPO)
• Updated DQN hyperparameters for CartPole
• Do not wrap channel-first image env (now natively supported by SB3)
• Removed hack to log success rate
• Simplify plot script