Convert ticks to 64-bit, added nanosecond precision to the API

Fixes https://github.com/libsdl-org/SDL/issues/5512
Fixes https://github.com/libsdl-org/SDL/issues/6731

test/testintersections.c

@@ -278,7 +278,8 @@ void loop()
 int main(int argc, char *argv[])
 {
     int i;
-    Uint32 then, now, frames;
+    Uint64 then, now;
+    Uint32 frames;
 
     /* Enable standard application logging */
     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);