Cleanup & bugfix

Cleanup & bugfix

* ObjectRef::set_local_animation: fix wrong lua return (should push a boolean, currently returns nil)
* ObjectRef::set_eye_offset: fix wrong lua return (should push a boolean, currently returns nil)
* Fix various Server functions which depends on RemotePlayer objet and return true/false when player object is nil whereas it's a caller implementation error. Change those bool functions to void and add sanitize_check call instead. Current callers are always checking player object validity
* Optimize Server::setClouds : use CloudParams object ref instead of attribute deserialization from structure & perform RemotePlayer::setCloudParams directly in server class like many other calls
* Optimize Server::SendCloudParams: use CloudParams object ref instead of deserialized attributes