Unshare public conversations from the title pane on web app

Only show the unshare button on public conversations created by the
currently logged in user. Otherwise hide the button

Set conversation.isOwner = true only if currently logged in user
shared the current conversation.

This isOwner information is passed by the get shared conversation API
endpoint

src/interface/web/app/components/chatMessage/chatMessage.tsx

@@ -196,6 +196,7 @@ export interface ChatHistoryData {
     agent: AgentData;
     conversation_id: string;
     slug: string;
+    is_owner: boolean;
 }
 
 function sendFeedback(uquery: string, kquery: string, sentiment: string) {