Improve Python bindings and release workflow

[maebli]

Summary

• add parse, parse_records, and render as an explicit Python API that accepts hexadecimal text or raw bytes and returns native Python objects where appropriate
• validate frame input, output formats, and 16-byte AES keys with clear Python exceptions while retaining the legacy string APIs
• ship type information and build the binding with the Rust parser's decryption feature
• add wheel-level tests, including a real encrypted wireless telegram
• validate package/tag versions on CI, test pull requests before release builds, merge artifacts into a predictable publish directory, and restrict PyPI upload to release tags

Why

The existing binding exposed serialized JSON strings instead of normal Python values, silently ignored malformed decryption keys, and did not enable the parser's decryption feature. The Python workflow also only exercised the package after a release tag was pushed, leaving API and packaging regressions undetected until publish time.

Impact

Callers can use a conventional typed Python API, pass either bytes or readable hex, and decrypt supported M-Bus frames with a 16-byte AES key. Existing m_bus_parse and parse_application_layer imports remain available.

Validation

• cargo fmt --all -- --check
• cargo check -p pymbusparser
• cargo clippy -p pymbusparser --all-targets -- -D warnings
• cargo test -p m-bus-core --features decryption
• cargo test -p m-bus-parser --features std,decryption
• release wheel build with Maturin and six installed-wheel unittest cases
• Maturin source-distribution build and content inspection
• actionlint .github/workflows/python.yml