Redact TLS keyfile password from client repr

[dfgvaetyj3456356-hash]

Summary

• redact tlsCertificateKeyFilePassword when rendering MongoClient/AsyncMongoClient repr output
• preserve existing repr formatting for non-sensitive options
• add sync and async unit regression coverage

Why

tlsCertificateKeyFilePassword is a passphrase for encrypted client certificate key files. Before this change, creating a client with that option and logging or inspecting repr(client) included the raw passphrase. This keeps the option visible for debugging while avoiding disclosure of the secret value.

This is intentionally scoped to the TLS keyfile passphrase and does not touch authMechanismProperties, which is already covered by a separate open PR.

Test

python -m pytest test\test_client.py::ClientUnitTest::test_repr_redacts_tls_certificate_keyfile_password test\asynchronous\test_client.py::AsyncClientUnitTest::test_repr_redacts_tls_certificate_keyfile_password -q
python -m py_compile pymongo\synchronous\mongo_client.py pymongo\asynchronous\mongo_client.py test\test_client.py test\asynchronous\test_client.py
git diff --check