feat(python): add __repr__ and to_dict to all SDK types

[johnpmitsch]

Summary

Adds __repr__ and to_dict() to every PyO3-exposed type in the Python SDK so they print readably (Endpoint { id: \"abc\", ... } instead of <builtins.Endpoint object at 0x...>) and convert cleanly to a native Python dict for JSON serialization, comparison, and logging.

• New python_repr_dict! macro in crates/core/src/python_macros.rs emits both methods. Each pyclass module gets a python_repr_impls block listing one call per type (~160 types).

• Workspace pyo3 gains multiple-pymethods so the macro can attach its own #[pymethods] impl beside any existing one.

• __repr__ delegates to Rust Debug; to_dict uses pythonize over the type's Serialize impl.

• Sensitive fields stay redacted in both repr() and to_dict():

  • SdkFullConfig.api_key (closes a latent leak — the derived Debug previously printed the raw key)
  • EndpointToken.token
  • EndpointJwt.public_key

  Per-type hand-rolled #[pymethods] blocks mirror the manual Debug redaction by overwriting the sensitive key with \"[redacted]\" after pythonize.

• Per-language wrapper types (StreamWebhookDestination / StreamS3Destination / StreamAzureDestination / StreamPostgresDestination / StreamKafkaDestination, the 8 webhook template wrappers, PyStream, PyListStreamsResponse) all expose the same surface.

Docs: CLAUDE.md gains a Python __repr__ and to_dict subsection that documents the macro and the redaction workflow for credential-bearing types; python/README.md mentions both methods in Language conventions.

Closes DX-5563

Test plan

• cargo check — all crates compile (python, node, ruby features)
• just lint — cargo clippy --workspace --lib --tests -- -D warnings clean
• cargo test -p quicknode-sdk --lib — 204 tests pass, including a new sdk_full_config_debug_redacts_api_key regression test
• just python-build — wheel + stubs regenerate; def __repr__ and def to_dict each appear 182 times in python/quicknode_sdk/_core/__init__.pyi
• just node-build and just ruby-build — unaffected (macro is gated behind feature = \"python\")
• Smoke-tested in Python:
  • repr(SdkFullConfig(api_key=\"x\")) contains \"[redacted]\", not \"x\"
  • SdkFullConfig(...).to_dict()[\"api_key\"] == \"[redacted]\"
  • Nested config round-trips through json.dumps
  • Wrapper types (StreamWebhookDestination) show inner attributes in repr and to_dict
• Run python/examples/admin.py end-to-end against a real API key to verify the new repr / to_dict demo block prints as expected