Enhance documentation and validation for rustls-rustcrypto

- Updated README.md to include detailed supported cipher suites, feature usage examples, and simplified feature sets.
- Expanded validation/README.md with comprehensive descriptions of validation crates, their purposes, and usage instructions.
- Added esp32-test/README.md detailing the ESP32 TLS test suite, including setup, features, and troubleshooting.
- Created rustls-real-socket-test/README.md for validating TLS functionality using real sockets, with extensive usage and configuration details.

Author: stevefan1999-personal