GA4 Support

[barbun]

Issue

The current version of the tool utilises Google Analytics Reporting API which has hit sunset on July 1, 2024, effectively rendering ga-extractor tool unusable.

Additionally, the DB schema in the latest Umami version is no longer compatible with this tool.

Proposed solution

• Update the code to work with Google Analytics Data API which is the replacement API to pull the data from GA4.
• Update Umami migration to work with the latest DB schema.

Summary of changes

• Added Google Analytics Data API library as a replacement for Reporting API.
• Changed the implementation to work with the new API library.
• Adjusted the setup function to work with property ID (GA4) instead of retired Table ID (Universal Analytics).
• Added config YAML validation.
• Updated UMAMI migration to work with the latest Umami version DB schema.
• Added miscellaneous adjustments to code structure in line with the best coding practices.
• Added sensible .gitignore.
• Updated tests.
• Updated README.md to reflect all the changes