Allow opening Javadoc in browser

I often want to view the Javadoc in the browser for easier reading, or to read package/module documentation (which afaik isn't easily viewable somehow inside VS Code).

Environment

• Operating System: Windows 10
• JDK version: 13.0.1
• Visual Studio Code version: 1.41.1
• Java extension version: 0.55.1

Steps To Reproduce

option 1:

1. hover over an element

option 2:

1. trigger autocompletion for an elemention

Current Result

option 1:

option 2:

Expected Result

I'd like for the pop-up dialogs to have an icon which opens the Javadoc of the element in the default browser. I'd already be very happy if this would work for just JDK classes, but ideally this would also work for Maven dependencies.

使用复现中描述的悬停和补全文档弹窗作为入口点。检查 Javadoc 如何针对 JDK 类和 Maven 依赖项进行解析；完成标准是两个弹窗都提供一个可打开相关 Javadoc 的浏览器操作，如果依赖项支持不可用，仅支持 JDK 也可以接受。