v0.16.0 of op_rest_api_client

A lightweight and flexible Dart HTTP client for RESTful APIs with structured error handling via op_result and support for identity-based authentication and token refresh. Changelog excerpt: ### Added - Added optional structured request/response logging through OpRestApiClientLogger. - Added OpRestApiClientLogEntryand OpRestApiClientLogDirectionas public logging models. - Request and response logs include method, URL, headers, body, status code, error type, and retry status where applicable. - Sensitive headers are sanitized before being passed to the logger, including authorization, cookie, API key, access-token, and refresh-token headers. ### Notes - Request and response [...]