fix(frontend): remove right panel and reduce chat section width (#2012)

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

---------

Co-authored-by: Antoine Dewez <antoinedewez@MacBook-Pro-de-Antoine.local>

frontend/app/chat/[chatId]/page.tsx

@@ -1,6 +1,5 @@
 "use client";
 
-import { useMenuWidth } from "@/lib/components/Menu/hooks/useMenuWidth";
 import { useKnowledgeToFeedContext } from "@/lib/context/KnowledgeToFeedProvider/hooks/useKnowledgeToFeedContext";
 import { useCustomDropzone } from "@/lib/hooks/useDropzone";
 import { cn } from "@/lib/utils";
@@ -13,7 +12,6 @@ import { useChatsList } from "./hooks/useChatsList";
 const SelectedChatPage = (): JSX.Element => {
     const { getRootProps } = useCustomDropzone();
     const { shouldDisplayFeedCard } = useKnowledgeToFeedContext();
-  const { shouldDisplayRightSideBar, OPENED_MENU_WIDTH } = useMenuWidth();
 
     useChatsList();
     useChatNotificationsSync();
@@ -30,7 +28,7 @@ const SelectedChatPage = (): JSX.Element => {
                 {...getRootProps()}
             >
                 <div
-          className={`flex flex-col flex-1 w-full max-w-5xl h-full dark:shadow-primary/25 overflow-hidden p-2 sm:p-4 md:p-6 lg:p-8`}
+                    className={`flex flex-col flex-1 w-full max-w-4xl h-full dark:shadow-primary/25 overflow-hidden p-2 sm:p-4 md:p-6 lg:p-8`}
                 >
                     <div className="flex flex-1 flex-col overflow-y-auto">
                         <ChatDialogueArea />
@@ -38,12 +36,6 @@ const SelectedChatPage = (): JSX.Element => {
                     <ActionsBar />
                 </div>
             </div>
-      {shouldDisplayRightSideBar && (
-        <div
-          className="h-full bg-highlight"
-          style={{ width: OPENED_MENU_WIDTH }}
-        />
-      )}
         </div>
     );
 };