(v3.0.8) NormalizeAction Wrapper migration from Sinergym Environment Module

[AlejandroCN7]

Description

In this PR, normalization of action space functionality is migrated from an environment flag to an individual wrapper.

Motivation and Context

• I have raised an issue to propose this change (required for new features and bug fixes)

Fixes #367

For more information about motivation, read the closed issue.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (update in the documentation)
• Improvement (of an existing feature)
• Others

Checklist:

• I've read the CONTRIBUTION guide (required)
• My change requires a change to the documentation.
• I have updated the tests.
• I have updated the documentation accordingly.
• I have reformatted the code using autopep8 second level aggressive.
• I have reformatted the code using isort.
• I have ensured cd docs && make spelling && make html pass (required if documentation has been updated.)
• I have ensured pytest tests/ -vv pass. (required).
• I have ensured pytype -d import-error sinergym/ pass. (required)

Changelog:

• Added a new wrapper called NormalizeAction.
• Updated environment module: Deleted normalization_flag attribute and all its functionality.
• Fixed tests and added tests for new wrapper.
• Updated documentation and added a section for this wrapper.
• Updated scripts examples for DRL training and loading models.
• Updated notebooks.
• Updated try_env.py example.

Extra

• Updated docstrings in DiscretizeEnv wrapper.