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

src/power/emscripten/SDL_syspower.c

@@ -25,7 +25,6 @@
 
 #include <emscripten/html5.h>
 
-
 SDL_bool
 SDL_GetPowerInfo_Emscripten(SDL_PowerState *state, int *seconds, int *percent)
 {