refactor(core): log warnings for non-prod node envs

packages/core/src/utils/log.ts

@@ -0,0 +1,7 @@
+const productionEnvs = ['production', 'prod']
+
+export const warn = (message: string, ...args: any[]) => {
+  if (!productionEnvs.includes(__ENV__ || '')) {
+    console.warn(`[Vue Flow]: ${message}`, ...args)
+  }
+}