Changed chat behaviour

added recoil value isMobile to determine which chat to display and
style. #1978

changed the player to actually span across the viewport without the
black borders around it.

web/components/ui/Sidebar/Sidebar.module.scss

@@ -9,6 +9,7 @@
     position: sticky;
     top: var(--header-h);
     display: block;
+    height: calc(100vh - var(--header-h));
     max-height: calc(100vh - var(--header-h));
   }
 }

web/components/ui/Sidebar/Sidebar.tsx

@@ -26,6 +26,7 @@ export default function Sidebar() {
         usernameToHighlight={chatDisplayName}
         chatUserId={chatUserId}
         isModerator={false}
+        isMobile={false}
       />
       <ChatTextField />
     </Sider>