FIX: Python - add metadata.quality.Parameter class; docstring and other formatting; change setup procedure

[dmeaux]

Fixes:

• Added the Parameter class to the metadata.quality module.
• Added type-hinting for return type of the metadata.quality.Measure.parameter attribute.
• Fixed the metadata.service.OperationMetadata.parameters attribute type-hinting to return a Sequence.
• Reformatted various docstrings to Google-style docstrings, which increases legibility in the docstrings and the online documentation.
• Updated the setup, development, test, documentation, and build processes to use a pyproject.toml file, modernizing the dependency management process.