Slow performance for alias lookup

In Visual Studio Code, the ctrl + F5 keyboard shortcuts translates PowerShell command aliases. The performance of this leaves a lot to be desired, and sometimes results in a confusing end user experience when you're rapidly moving the cursor around the editor.

Can we improve performance of this function, to make it more usable? If necessary, we could cache a lookup table, and either invalidate it on-demand, or periodically update it with a background worker.

Cheers,
Trevor Sullivan
https://trevorsullivan.net
https://twitter.com/pcgeek86

该 issue 指出了由 Visual Studio Code 的 ctrl+F5 快捷键触发的 PowerShell 别名查找，但没有指出任何文件、测试或入口点。先追踪这次查找，并建立一个可复现的快速光标移动性能案例；完成的标准是：在没有所描述的令人困惑行为的情况下，该查找的可用性有可测量的提升。