feat(esp_isotp): add ISO-TP protocol component's echo example (IEC-376)

[eternal-echo]

Checklist

• [x] Component contains License
• [x] Component contains README.md
• [x] Component contains idf_component.yml file with url field defined
• [x] Component was added to upload job
• [x] Component has an example project
• [x] Component has a test_app (pytest-based testing)
• [x] CI passing

Change description

Add ESP-IDF ISO-TP Component

This PR adds the esp_isotp component, providing a complete ISO-TP (ISO 15765-2) protocol implementation for ESP-IDF. ISO-TP is essential for automotive and industrial applications requiring CAN-based diagnostic communication.

Key Features

• Complete ISO-TP Protocol: Full implementation of ISO 15765-2 standard
• Multi-Frame Support: Handles both Single Frame (SF) and Multi-Frame (MF) transmission
• Flow Control: Configurable Block Size and STmin parameters
• Thread-Safe Design: Safe for use in multi-threaded applications with interrupt context support
• Memory Efficient: Optimized buffer management for embedded systems
• QEMU Testing: Complete test suite running in QEMU environment

Component Structure

esp_isotp/
├── LICENSE                   # Apache 2.0 License
├── README.md                # Comprehensive documentation
├── idf_component.yml        # Component manifest with URL
├── include/esp_isotp.h      # Public API
├── src/                     # Implementation files
├── isotp-c/                 # Git submodule for protocol core
└── examples/echo/           # Echo example with pytest

Testing

• Automated Testing: Comprehensive pytest suite with QEMU integration
• Test Coverage: Single/Multi-frame, flow control, error scenarios
• CI Ready: Tests run automatically without hardware requirements
• Example Project: ISO-TP echo server demonstrating bidirectional communication

Integration Status

• ✅ Added to upload job workflow
• ✅ Component auto-discovered by clang-tidy test_app
• ✅ All required files present and properly configured
• ✅ Follows ESP-IDF coding standards and best practices

Use Cases

• Automotive diagnostic systems (UDS over CAN)
• Industrial CAN communication requiring >8 byte messages
• IoT gateways with CAN connectivity
• ESP32-based diagnostic tools and interfaces

This component fills a critical gap for CAN-based applications in the ESP-IDF ecosystem, providing a robust, production-ready ISO-TP implementation with comprehensive testing and documentation.

[eternal-echo]

Please bump the component version.

And this leftover nitpick: #563 (comment)

Could I get a Copilot reviewer first? :)