text: Title: Table selected cell
  Body: When a cell with default background color is active, a highlight color is applied.
  ![image](https://user-images.githubusercontent.com/8092993/58188953-8b3d7280-7c87-11e9-9c2c-a4ef9c7bf515.png)
  
  When a cell with a `style_**` background color is active, the highlight color is not visible.
  ![image](https://user-images.githubusercontent.com/8092993/58188995-a01a0600-7c87-11e9-8d0e-d293f80df5eb.png)
  
  This also applies to selected cells.
  ![image](https://user-images.githubusercontent.com/8092993/58189044-b32cd600-7c87-11e9-8f32-69900b914190.png)
  
  The active/selected styling is currently done through css [here](https://github.com/plotly/dash-table/blob/master/src/dash-table/components/Table/Table.less#L249) and [here](https://github.com/plotly/dash-table/blob/master/src/dash-table/components/Table/Table.less#L261) -- this styling should be done through the styling pipeline / derivations. For example, the data cells [here](https://github.com/plotly/dash-table/blob/master/src/dash-table/derived/cell/wrapperStyles.ts)
  
  The change should be similar to what has already been done for the active cell's border [here](https://github.com/plotly/dash-table/blob/master/src/dash-table/derived/edges/data.ts#L78)