Add new FullPage component

Signed-off-by: Charles de Dreuille <charles.dedreuille@gmail.com>

.storybook/preview.tsx

@@ -5,7 +5,7 @@ import addonLinks from '@storybook/addon-links';
 import { definePreview } from '@storybook/react-vite';
 import { useEffect } from 'react';
 import { TestApiProvider } from '@backstage/test-utils';
-import { Content, AlertDisplay } from '@backstage/core-components';
+import { AlertDisplay } from '@backstage/core-components';
 import { apis } from './support/apis';
 import { useGlobals } from 'storybook/preview-api';
 import { UnifiedThemeProvider, themes } from '@backstage/theme';
@@ -146,9 +146,7 @@ export default definePreview({
           {/* @ts-ignore */}
           <TestApiProvider apis={apis}>
             <AlertDisplay />
-            <Content>
-              <Story />
-            </Content>
+            <Story />
           </TestApiProvider>
         </UnifiedThemeProvider>
       );