This adds support for detecting the `CommandManager.execute` method in
the unique command use query.
This may not be the best way to implement this. There's a method
`hasUnderlyingType` on `this.getReceiver().getType()`, but I couldn't
really figure out how to get it recognize `CommandManager`. It might be
possible if we can construct the type of `CommandManager`, but this will
probably include the filepath to the `CommandManager` class, which might
not neccessarily be something we want: moving the `CommandManager` class
should not require updating the query. I'm very happy to hear other
suggestions.
This query ensures that all of our files marked as "pure" remain that
way. In this case "pure" means that it does not depend on vscode and
can therefore be run in tests outside of a runtime environment.
This commit also explicitly moves all of our "pure" files to the
`src/pure` directory.
