Allow shader global uniforms to be arrays

[thompsop1sou]

Right now, Godot allows regular uniforms to be arrays. See the PR when this was implemented: Added support for uniform arrays in shaders.

However, it still doesn't allow you to do this for global uniforms. The docs list out all of the possible global shader parameter types, and arrays don't appear to be included. You can also see this limitation when adding a shader global in the project settings dialog.

No options for arrays of any kind.

Would it be possible to add arrays as a global uniform type?