refactor(layouts): simplify MainLayout and enhance styling

- Removed unused imports and performance monitoring hooks from MainLayout.
- Updated layout structure to improve responsiveness and styling, including sticky header and optimized content padding.
- Adjusted home page layout to reduce margin and improve spacing for better visual consistency.
- Enhanced TodoList component with collapsible sections for improved user interaction and task management.
- Streamlined project and schedule pages by removing unnecessary margin adjustments, ensuring a cleaner layout.

worklenz-frontend/src/pages/projects/projectView/project-view.tsx

@@ -360,14 +360,14 @@ const ProjectView = React.memo(() => {
   // Show loading state while project is being fetched or translations are loading
   if (projectLoading || !isInitialized || !translationsReady) {
     return (
-      <div style={{ marginBlockStart: 70, marginBlockEnd: 12, minHeight: '80vh' }}>
+      <div style={{ marginBlockEnd: 12, minHeight: '80vh' }}>
         <SuspenseFallback />
       </div>
     );
   }
 
   return (
-    <div style={{ marginBlockStart: 70, marginBlockEnd: 12, minHeight: '80vh' }}>
+    <div style={{ marginBlockEnd: 12, minHeight: '80vh' }}>
       <ProjectViewHeader />
 
       <Tabs