Control panel should show numbers in each population

It's quite difficult to determine the number of cells in a generated network, and especially if you set a cell density you're never sure of the total number in an instance of the network. A good place for this would be the Control Panel, where you can list the instances if you expand the individual cell populations. What would be better is if the number in each population was visible beside the name, and mayne the total at network e.g.

> network (30)
  > E2 (6)
  > L1 (3)
...

首先定位 Control Panel 及其网络和细胞群体列表组件。查看当前如何表示群体实例和细胞数量，然后按照 issue 中的显示方式，在每个群体旁边以及网络旁边添加数量。完成标准是：展开的条目显示群体数量，网络显示其总数。