fix: split view with a few messages appeared sticky at the top

ts/components/SplitViewContainer.tsx

@@ -11,6 +11,7 @@ const StyledSplitView = styled.div`
   max-height: 100%;
   min-height: 0;
   display: flex;
+  flex-grow: 1;
   flex-direction: column;
 `;
 

ts/session/conversations/ConversationController.ts

@@ -166,7 +166,7 @@ class ConvoController {
   public getNicknameOrRealUsernameOrPlaceholder(pubKey: string): string {
     const conversation = ConvoHub.use().get(pubKey);
     if (!conversation) {
-      return pubKey;
+      return PubKey.shorten(pubKey);
     }
     return conversation.getNicknameOrRealUsernameOrPlaceholder();
   }

ts/session/types/PubKey.ts

@@ -88,7 +88,7 @@ export class PubKey {
     const pk = value instanceof PubKey ? valAny.key : value;
 
     if (!pk || pk.length < 8) {
-      throw new Error('PubKey.shorten was given an invalid PubKey to shorten.');
+      return pk;
     }
 
     return `(${pk.substring(0, 4)}...${pk.substring(pk.length - 4)})`;