Adding a proxy in the subscription management section.

[Netvek123]

Verify steps

• 我已在标题简短的描述了我所需的功能
• 我已在 Issue Tracker 中寻找过，但未找到我所需的功能
• 这是向 GUI 程序提出的功能请求，而不是内核程序
• 我未在最新的测试版本找到我所需的功能

操作系统

Windows

描述

Make it possible to add a proxy server to update a subscription through the subscription management section.

[Netvek123]

In the same window, add a button to check (test) the proxy's performance. And add a response time indicator. Each subscription has its own separate proxy server.