Storybook fix dark mode (#4865)

preview has now also a dark background & added a one click change theme
button

<img width="994" alt="Bildschirmfoto 2024-04-06 um 18 27 45"
src="https://github.com/twentyhq/twenty/assets/48770548/95f12617-e48f-4492-9b51-13410aff43ee">

packages/twenty-front/src/testing/ComponentStorybookLayout.tsx

@@ -1,8 +1,6 @@
 import styled from '@emotion/styled';
 
 const StyledLayout = styled.div<{ width?: number }>`
-  background: ${({ theme }) => theme.background.primary};
-  border: 1px solid ${({ theme }) => theme.border.color.light};
   border-radius: 5px;
 
   display: flex;