Better language support for C++ would be appreciated!

[cbedhoam620]

Now use GDExtension, and then manually use godot-cpp to create project templates, a little too cumbersome, I hope to be able to build-in language support, of course, we do not expect to be able to directly in the Godot built-in editor can write cpp code, but we want to be able to Godot through the Node or control right-click on the attached script, can be popped up in the " Set script for node" dialog box, the language drop-down list box, you can add the option of C++, and automatically configure the godot-cpp project template to simplify the development.

[Calinou]

Thanks for the proposal! Consolidating in #573.