Allow query results view to act as a panel

[p0]

Is your feature request related to a problem? Please describe.
Currently, our query results view is an editor webview, which consigns it to one of the editor panes. Occasionally, I find that shifting focus to and from it interacts with where VS code will place newly created editor windows, which can be annoying and unpredictable.

This also represents a potentially suboptimal use of screen real estate: In normal CodeQL development, the panel can be used to examine query logs, but often it is not part of the action; being able to use it for query results would free up more space for source code.

Describe the solution you'd like
With the advent of webview views, extensions can contribute general webview-based UIs to the side bar and panels. The highest amount of flexibility would be afforded if we could toggle between the results being displayed in an editor pane and a side bar/panel tab.

I actually think making it live in the panel permanently would be the more natural choice, but I could imagine others being less convinced.

[aeisenberg]

I think this is a really neat idea. It could be useful in some situations, though I'm reluctant to completely remove the option to view in an editor. Ideally, you should be able to look at the results in a view or an editor.

My concern about seeing the results in a view is that it's often the case (at least for me) that we need significant vertical or horizontal width to see enough results, otherwise things will be cramped.

This is something worth experimenting with and if it's easy to keep both, I think that would be great. One idea would be to add a button in the results view that will toggle between using an editor and a view. At this point, unless we do some big refactoring, we are limited to having a single results view at a time.