✨ Copy Link to Code

### Description

It would be awesome if CodeEdit could copy links to code when the workspace has a remote on GitHub.

I'd imagine it's on a key command like Command-shift-c as well as a button in the file inspector. It would only be abled when source control is on a branch that is tracked by a remote on GitHub. Then we can craft a link to the correct branch/file/lines using GitHub's permalink format.

首先跟踪 issue 中提到的文件检查器、键命令处理和源代码控制分支状态。检查 GitHub 远程仓库和选定文件行的公开方式，然后验证命令和检查器按钮仅对 GitHub 跟踪的分支启用，并生成正确的 GitHub permalink。

由索引模型根据 Issue 内容生成。