Migrate build backend from Poetry to Hatch and add templates

[anushacs-dell]

This PR significantly enhances the zoo-template-common project by introducing modern Python packaging standards, comprehensive CI/CD workflows, governance documentation, and improved project maintenance tools.

Project Configuration & Dependencies:

• Migrated from Poetry to Hatch for build system and dependency management
• Updated pyproject.toml to use PEP 621 standard for project metadata
• Added new dependencies: attrs, cwl-utils>=0.14
• Updated Python version requirement to >=3.10 with explicit support matrix (3.10, 3.11, 3.12)
• Minor formatting improvements in common_execution_handler.py for consistency
• Added project URLs for Issues and Changelog

GitHub Workflows & CI/CD:

• New: package.yaml - Comprehensive CI/CD workflow replacing outdated publish-pypi.yml
• Runs on Python 3.10, 3.11, and 3.12
• Code quality checks: Ruff linting and formatting
• Automated testing with Hatch
• Automated PyPI publishing on version tags with validation
• Removed: publish-pypi.yml - Replaced with modern workflow

Github Templates,Documentation,Governance:

• Added Bug Report Template (.github/ISSUE_TEMPLATE/bug_report.md) with standard sections
• Added Feature Request Template (.github/ISSUE_TEMPLATE/feature_request.md) for enhancements
• Added Pull Request Template (.github/PULL_REQUEST_TEMPLATE.md) with checklist
• Added comprehensive CHANGELOG.md tracking all releases from v0.1.0 to v0.1.8
• Added CODE_OF_CONDUCT.md referencing OSGeo Code of Conduct
• Updated CONTRIBUTING.md file for hatch based workflow

Testing & Development:

• Added tests/test_placeholder.py with initial test scaffold
• Configured pytest in pyproject.toml with test environment setup
• Added zoo_template_common/__about__.py for centralized version management