[Feature] Change specific data point symbol by hover

### What problem does this feature solve?

Cannot change data point symbol by hover.
For example, if I hover on data point `['Tue', 230]` in https://echarts.apache.org/examples/en/editor.html?c=line-simple, I wanna highlight the point with different symbol, such as diamond or triangle.
I know there is `markPoint` option, but as far as I know, it doesn't highlight data point by hover.

### What does the proposed API look like?

Change specific data point symbol by hove. If it's not hovered, display the normal data point.