[comp:time-picker] 体验优化

[danranVm]

• I have searched the issues of this repository and believe that this is not a duplicate.

What problem does this feature solve?

• 当 value 和 defaultOpenValue 都为空的时候，默认高亮当前时间。
• 鼠标悬浮在面板的任意位置时，都应该出现滚动条（去掉容器的 padding）

What does the proposed API look like?

[idux-bot]

Translation of this issue:

[COMP: TIME-PICKER] Experience Optimization

• i Have Searched The [https://github.com/iduxfe/idux/issues) of this repository and believe That this is not a duplicate.

What proBLEES THIS Feature SOLVE?

• When Value and DefaultOpenValue are empty, the default is highlighted.
• When the mouse is suspended in any position of the panel, the scroll bar should appear (remove the container Padding)

What does The proposed API Look Like?

[danranVm]

closed #886