Use system nickname or first name for incoming group calls

ts/util/callingGetParticipantName.ts

@@ -4,7 +4,17 @@
 import type { ConversationType } from '../state/ducks/conversations';
 
 export function getParticipantName(
-  participant: Readonly<Pick<ConversationType, 'firstName' | 'title'>>
+  participant: Readonly<
+    Pick<
+      ConversationType,
+      'firstName' | 'systemGivenName' | 'systemNickname' | 'title'
+    >
+  >
 ): string {
-  return participant.firstName || participant.title;
+  return (
+    participant.systemNickname ||
+    participant.systemGivenName ||
+    participant.firstName ||
+    participant.title
+  );
 }