ackId function
The <rule>:<locale>:<key> identifier for an issue, or null if the
issue lacks the parts an ack needs (key is always required; a
source-only issue uses the literal source locale slot).
Implementation
String? ackId(Issue issue) {
if (issue.key == null) return null;
final locale = issue.locale ?? 'source';
return '${issue.ruleName}:$locale:${issue.key}';
}