🤔 [QUESTION] 堆叠折线双轴图无法设置y轴title么？

### 🐛 Question description [Please make everyone to understand it]

### 💻 Link to minimal reproduction

Please provide a link by forking these links [g2plot](https://codesandbox.io/s/g2plot-reproduction-template-gyej1) or GitHub repo. What is a minimal reproduction, and why is it required?

### 🏞 Expected result

### 🚑 Any additional [like screenshots]

* **G2Plot Version**:
* **Platform**:

Start with the linked G2Plot CodeSandbox reproduction template and reproduce the reported stacked dual-axis line chart configuration. The issue provides no concrete reproduction, expected result, version, platform, file, or test; first determine whether y-axis titles are intended to be supported and record the exact configuration and behavior needed to define completion.

Written by the indexing model from the issue text.