Adds comprehensive performance testing suite

[tumbledwyer]

Introduces a new K6-based performance testing suite to validate system stability and performance under various load conditions.

New Features & Enhancements

• Comprehensive Performance Testing: Implements smoke, load, soak, and spike tests, each configured with specific scenarios and thresholds to rigorously assess system behavior.
• Automated Build & Deployment: Adds an esbuild process for K6 test scripts and a dedicated Dockerfile.perf-test to build a K6 runner image with Elasticsearch output.
• CI/CD Workflow Update: Enhances the GitHub Actions workflow to support building and pushing both the data generator and performance test Docker images using a matrix strategy.
• API Schema Expansion: Broadens the OpenAPI schema to include new form field types (e.g., for ID reading, QR codes, verification status) and introduces a new /attachments endpoint for file uploads, providing greater flexibility for UI components and data handling.

Refinements & Fixes

• Data Generator Refactoring: Renames existing performance-related files and Helm charts to data-generator to better reflect their role in populating test environments.
• Improved Test Reliability: Addresses various issues, including crypto reference errors, default user configurations, Bad Gateway handling, and ensures UUID generation consistency between local and Docker environments.
• Enhanced Reporting: Exports test summaries to stdout and summary.json, removing ANSI color codes for cleaner output.
• Optimized Resource Usage: Staggers initial authentication requests across VUs to prevent resource contention during test ramps and adds more robust error logging.