Implement SDL2 for Windowing + Input

[capnkenny]

Currently, GLFW is used as our primary Windowing and Input provider.

This ticket is to implement an alternative (SDL2) for Windowing and Input so that we can opt to use SDL2 + Vulkan in the current setup instead of GLFW + Vulkan.

What's involved:

• Implementing the SDL2 enum selection in the Vulkan Surface creation method
• Implementing the Windowing::SDL2 namespace
• Implementing the Input::SDL2 namespace (it will require Windowing to be finished)
• Implementing a way to choose between GLFW or SDL2

To be specific, we are not removing GLFW - just adding SDL2 as an alternative

[Perksey]

Has Matt been kidnapped or something?!?!

[RubyNova]

Lol, no, its just GLFW doesn't work in some cases

[capnkenny]

Lol, no, its just GLFW doesn't work in some cases

This indeed helps with bringing more compatibility for non-desktop related use cases in the future, as well as cases where GLFW might not be the best option