Create bridge device on GUI.

[gilbertoferreira]

Hello there.
Often I need create some bridge in Linux in order do work fine with Virtmanager for instance.
But when using Deepin Linux I can't create a bridge on GUI.
Here's an example in KDE Plasma.

[BLumia]

@meiyixiang 需求：希望能通过设置界面创建（网络）桥接设备。