🐛 [BUG]分组条形图在处理日期时显示异常

### 🐛 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.

bug link: https://codesandbox.io/s/g2plot-issue-template-forked-rvo6e

在日期格式为年月日时分秒时, 显示异常. 一方面是一些字段被显示为了NaN, 另一方面是日期字段显示不全

### 📷 Step to reproduce

### 🏞 Expected result

### 🚑 Any additional [like screenshots]

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

Start with the linked CodeSandbox reproduction and its index.ts entry point, then compare the grouped bar chart behavior for full date-and-time values. The issue is fixed when no fields render as NaN and the complete date value is displayed; the payload does not name a repository test to run.

Written by the indexing model from the issue text.