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/ui/input/components/TextArea.tsx

@@ -29,7 +29,6 @@ const StyledTextArea = styled(TextareaAutosize)`
   line-height: 16px;
   overflow: auto;
   padding: ${({ theme }) => theme.spacing(2)};
-  padding-top: ${({ theme }) => theme.spacing(3)};
   resize: none;
   width: 100%;