feat: Refactor contact form and improve 404 page

This commit refactors the contact form for better reusability and moves it from the global footer to a dedicated section on the homepage. Additionally, it enhances the user experience on the 404 page.

Key changes:
- The `ContactUsForm` component is now configurable with props for grid layout (`columnsPerRow`) and button text, making it more versatile.
- The contact form has been removed from the shared footer in the main layout and is now explicitly included only on the homepage.
- The 404 "Not Found" page has been updated to include a direct link to the homepage for easier navigation.
- Minor style adjustments were made to the 404 page layout and input field padding for improved visual consistency.

app/_components/InputGroup.tsx

@@ -38,7 +38,7 @@ function InputGroup({
               : isFocused
               ? "border-(--primary)"
               : "border-gray-200"
-          } p-2 rounded-lg w-full outline-none`}
+          } p-2 py-3 rounded-lg w-full outline-none`}
           id={id}
           {...rest}
           onChange={handleChange}