Code completion of the generic type parameter in GetNode

Hello,

I've had the pleasure of trying the extension, and enjoyed the code completion of the node name string in GetNode(...).
However, typing out the generic type parameter for GetNode still feels tedious to me, so I thought that the code completion could be extended with that information. I think this would also benefit the majority of the users.

For example in the current case if you type as far as `GetNode(` then code completion will give you options like e.g. `"MainCharacterSprite", "CollisionShape2D"`.

The code completion could be extended so that typing `GetNode` would yield the following completion options for the scene from the previous example: `GetNode("MainCharacterSprite")`, `GetNode("CollisionShape2D")`.

Is it possible to provide this richer code completion from the extension?