* --stacktrace signMavenJavaPublication
* added temporary step "Debug gradle signing"
* cd bindings/java
* use GPG_PRIVATE_KEY and GPG_PASSPHRASE
* use secrets.GPG_PRIVATE_KEY and GPG_PASSPHRASE
* Java needs to call `whisper_full_default_params_by_ref()`, returning struct by val does not seem to work.
* added convenience methods to WhisperFullParams
* Remove unused WhisperJavaParams