Added JSON output to listGroups and allowed json to be activated with -j (#401)

[signal-cli] / src / main / java / org / asamk / signal / manager / helper / UnidentifiedAccessSenderCertificateProvider.java

package org.asamk.signal.manager.helper;

public interface UnidentifiedAccessSenderCertificateProvider {

    byte[] getSenderCertificate();
}