Created by: nickyfantasy

According to @varunarora design,

https://github.com/PaddlePaddle/VisualDL/files/2255325/VDL_DesignSpec-1.pdf

We should show / select runs in top bar.

Runs are global among all components, it makes more sense to put it in a global space.

Mouse hover the runs should show dropdown to select / toggle run.