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/testdisplayinfo.c

@@ -29,8 +29,7 @@ print_mode(const char *prefix, const SDL_DisplayMode *mode)
             mode->w, mode->h, mode->refresh_rate);
 }
 
-int
-main(int argc, char *argv[])
+int main(int argc, char *argv[])
 {
     SDL_DisplayMode mode;
     int num_displays, dpy;
@@ -81,7 +80,7 @@ main(int argc, char *argv[])
                 SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "    MODE %d: failed to query (%s)\n", m, SDL_GetError());
             } else {
                 char prefix[64];
-                SDL_snprintf(prefix, sizeof (prefix), "    MODE %d", m);
+                SDL_snprintf(prefix, sizeof(prefix), "    MODE %d", m);
                 print_mode(prefix, &mode);
             }
         }