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.cjs

@@ -4,6 +4,7 @@ module.exports = {
     '!./src/modules/databases/**',
     '!./src/modules/object-metadata/**',
     '!./src/modules/object-record/**',
+    '!./src/modules/settings/serverless-functions/**',
     './src/modules/**/*.tsx',
     './src/modules/**/*.ts',
     '!./src/**/*.test.tsx',