Implement preview and code on highlighting in quick search panel

[Tsimopak]

When searching for something in the quick search panel, you would see it in uniform color except the pattern text:

The suggestion is to highlight it to the real colors it would have been colored if I would open the file, so for example variables in a certain color, string in other color and so on.

And the second idea is to be able to see +- X lines before and after, just to feel more the context of what search result I am looking at. Or just when moving between search results it would open it in watch mode, for a fast access, and when pressing ESC, it would return to the original file I was.

[TylerLeonhardt]

In the latest VS Code you can see preview now:

Screen.Recording.2024-02-02.at.2.58.14.PM.mov

since we have this, I think that my eyes focus a lot on the editor and less the quick pick... so I don't think the code highlighting in the quick pick is needed. Additionally, that'd be quite a lot of work since we don't have a concept of code highlighting there.

Give the preview stuff a try and let us know if you find any issues with it!

[TylerLeonhardt]

cc @andreamah