feat: user avatar images

- added user avatars for each user
- it will fetch user images from github or google and if there is no image then it will show initials

frontend/app/(app)/code/[id]/page.tsx

@@ -51,7 +51,7 @@ const getSharedUsers = async (usersToSandboxes: UsersToSandboxes[]) => {
         }
       )
       const userData: User = await userRes.json()
-      return { id: userData.id, name: userData.name }
+      return { id: userData.id, name: userData.name, avatarUrl: userData.avatarUrl }
     })
   )