PR and Regression testing for Go snippets

[ivanmkc]

This PR introduces new tooling for managing and validating Go snippets within the repository.

Key additions include:

• Go Snippets Runner (tools/go-snippets/runner.sh): A new script to build and run Go snippets, supporting both targeted execution for changed files and full regression testing. This script replaces the need for separate build_all.sh and run_all.sh scripts.
• Go Files to Test List (tools/go-snippets/files_to_test.txt): A new configuration file that lists all Go snippet files to be included in the build and run processes. It supports single files and multiple files for packages with shared dependencies, and allows for comments.
• Go Snippets PR Check (tools/go-snippets/check_go_snippets.sh): A new script to ensure that all .go files in the examples/go directory are properly referenced in files_to_test.txt, preventing new snippets from being overlooked in the test suite.
• CI Workflow Integration: The .github/workflows/go-snippets-pr-check.yaml workflow utilizes these new scripts for comprehensive Go snippet testing on pull requests and a weekly schedule.
  These new files establish a robust and centralized system for Go snippet management, ensuring consistency and test coverage.

[joefernandez]

@ivanmkc : Does this update have any dependencies on ADK Go releases beyond v0.1.0? If so, you should mark this as BLOCKED until an official release is available with these changes.