Update for SDL3 coding style (#6717)

I updated .clang-format and ran clang-format 14 over the src and test directories to standardize the code base.

In general I let clang-format have it's way, and added markup to prevent formatting of code that would break or be completely unreadable if formatted.

The script I ran for the src directory is added as build-scripts/clang-format-src.sh

This fixes:
#6592
#6593
#6594

(cherry picked from commit 5750bcb174)

test/testnative.h

@@ -22,8 +22,8 @@
 typedef struct
 {
     const char *tag;
-    void *(*CreateNativeWindow) (int w, int h);
-    void (*DestroyNativeWindow) (void *window);
+    void *(*CreateNativeWindow)(int w, int h);
+    void (*DestroyNativeWindow)(void *window);
 } NativeWindowFactory;
 
 #ifdef SDL_VIDEO_DRIVER_WINDOWS