Fix hello world application (#14880)

Updates of the hello-world application
- remove the old hello-world application
- adds an object "postCard"
- adds a serverlessFunction `create-new-post-card` that calls the twenty
api to create a new postCard record
- add a route trigger /post-card/create?recipient=John

packages/twenty-server/src/engine/workspace-manager/dev-seeder/core/utils/seed-feature-flags.util.ts

@@ -66,11 +66,6 @@ export const seedFeatureFlags = async (
         workspaceId: workspaceId,
         value: false,
       },
-      {
-        key: FeatureFlagKey.IS_DATABASE_EVENT_TRIGGER_ENABLED,
-        workspaceId: workspaceId,
-        value: false,
-      },
       {
         key: FeatureFlagKey.IS_CALENDAR_VIEW_ENABLED,
         workspaceId: workspaceId,