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/codegen-metadata.cjs

@@ -3,6 +3,7 @@ module.exports = {
   documents: [
     './src/modules/databases/graphql/**/*.ts',
     './src/modules/object-metadata/graphql/*.ts',
+    './src/modules/settings/serverless-functions/graphql/**/*.ts',
     './src/modules/object-record/graphql/*.tsx',
     './src/modules/metadata/graphql/*.ts',
   ],