Apply code formatting config to all source files

[WildWeazel]

#163 introduced a .editorconfig with code formatting rules. Reformat all .cs (and .gd?) files at once. Going forward devs should use this file in their IDE if possible, and format changes accordingly. But first let's settle on what the formatting rules should be.

I recommend we follow Godot's own C# style guide, and Microsoft's as a fallback. Discuss formatting here.