Serverless function UI (#6388)

https://www.figma.com/design/xt8O9mFeLl46C5InWwoMrN/Twenty?node-id=36235-120877

Did not do the file manager part. A Function is defined using one unique
file at the moment

Feature protected by featureFlag `IS_FUNCTION_SETTINGS_ENABLED`

## Demo


https://github.com/user-attachments/assets/0acb8291-47b4-4521-a6fa-a88b9198609b

packages/twenty-front/src/modules/activities/files/utils/downloadFile.ts

@@ -1,7 +1,7 @@
-import { REACT_APP_SERVER_BASE_URL } from '~/config';
+import { getFileAbsoluteURI } from '~/utils/file/getFileAbsoluteURI';
 
 export const downloadFile = (fullPath: string, fileName: string) => {
-  fetch(REACT_APP_SERVER_BASE_URL + '/files/' + fullPath)
+  fetch(getFileAbsoluteURI(fullPath))
     .then((resp) =>
       resp.status === 200
         ? resp.blob()