// Publish a message encrypted with a secp256k1 public key using waku lightpush. Use NULL for topic to use the default pubsub topic.
// peerID should contain the ID of a peer supporting the lightpush protocol. Use NULL to automatically select a node
// publicKey must be a hex string prefixed with "0x" containing a valid secp256k1 public key.
// optionalSigningKey is an optional hex string prefixed with "0x" containing a valid secp256k1 private key for signing the message. Use NULL otherwise
// If ms is greater than 0, the broadcast of the message must happen before the timeout
// (in milliseconds) is reached, or an error will be returned.
// optionalSigningKey is an optional hex string prefixed with "0x" containing a valid secp256k1 private key for signing the message. Use NULL otherwise
// If ms is greater than 0, the broadcast of the message must happen before the timeout
// (in milliseconds) is reached, or an error will be returned.