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-ui/src/theme/constants/ThemeDark.ts

@@ -9,6 +9,7 @@ import { BOX_SHADOW_DARK } from './BoxShadowDark';
 import { FONT_DARK } from './FontDark';
 import { TAG_DARK } from './TagDark';
 import { THEME_COMMON } from './ThemeCommon';
+import { CODE_DARK } from './CodeDark';
 
 export const THEME_DARK: ThemeType = {
   ...THEME_COMMON,
@@ -22,5 +23,6 @@ export const THEME_DARK: ThemeType = {
     name: 'dark',
     snackBar: SNACK_BAR_DARK,
     tag: TAG_DARK,
+    code: CODE_DARK,
   },
 };