Fix bug in custom exceptions and add doc strings

[benieric]

Issue #, if available:

Description of changes:

• Add docstrings
• run black . -l 100
• Fixing small bug in exceptions found while working on example notebooks:

  Traceback (most recent call last):
  File "/Volumes/workplace/sagemaker-core/end_user_experience/../src/generated/resources.py", line 79, in get_updated_kwargs_with_configured_attributes
  resource_defaults = load_default_configs_for_resource_name(
  File "/Volumes/workplace/sagemaker-core/end_user_experience/../src/generated/intelligent_defaults_helper.py", line 184, in load_default_configs_for_resource_name
  configs_data = load_default_configs()
  File "/Volumes/workplace/sagemaker-core/end_user_experience/../src/generated/intelligent_defaults_helper.py", line 79, in load_default_configs
  error = LocalConfigNotFoundError(file_path=file_path)
  File "/Volumes/workplace/sagemaker-core/end_user_experience/../src/generated/exceptions.py", line 65, in __init__
  super().__init__(file_path, message=message)
  TypeError: IntelligentDefaultsError.__init__() got multiple values for argument 'message'

Testing pytest -vv -s tst && black . -l 100 run example notebook

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