将条形图的shape设置为tick类型时，设置数据标签的位置为position: 'middle',此时会导致标签位置设置失效

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

> Please provide a link by forking these links [G2Plot](https://codesandbox.io/s/g2plot-issue-template-gzfdq?file=/index.ts) or GitHub repo, a minimal reproduction.

* _Required_ **Link to minimal reproduction**:

### 📷 Step to reproduce

### 🏞 Expected result

### 🚑 Any additional [like screenshots]

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

Start with the G2Plot issue template linked in the report and reproduce a bar chart using shape type `tick` with data-label position `middle`. Confirm that the label position is ignored, then identify the relevant chart and label implementation; done means the requested position works and the behavior is covered by a regression test. No source file or test path is named in the issue.

Written by the indexing model from the issue text.