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/testpower.c

@@ -54,14 +54,12 @@ report_power(void)
     if (seconds == -1) {
         SDL_Log("Time left: unknown\n");
     } else {
-        SDL_Log("Time left: %d minutes, %d seconds\n", (int) (seconds / 60),
-                (int) (seconds % 60));
+        SDL_Log("Time left: %d minutes, %d seconds\n", (int)(seconds / 60),
+                (int)(seconds % 60));
     }
 }
 
-
-int
-main(int argc, char *argv[])
+int main(int argc, char *argv[])
 {
     /* Enable standard application logging */
     SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);