Many of the structs found in internal.h (internal_windows.go) contain defines such as GLFW_WIN32_WINDOW_STATE
which gets replaced with a struct defined in win32platform_windows.go (win32_platform.h).
Originally, these structs where directly placed inside of internal_windows.go. However, to make it easier to add macOS
and Linux these cannot be in this file.
This commit separates the windows specific structs into the respective windows file and updates the field to be named
state.
Updates #2546
