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

build-scripts/clang-format-src.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+cd "$(dirname $0)/../src"
+
+echo "Running clang-format in $(pwd)"
+
+find . -regex '.*\.[chm]p*' -exec clang-format -i {} \;
+
+# Revert third-party code
+git checkout \
+    events/imKStoUCS.* \
+    hidapi \
+    joystick/controller_type.c \
+    joystick/controller_type.h \
+    joystick/hidapi/steam/controller_constants.h \
+    joystick/hidapi/steam/controller_structs.h \
+    libm \
+    stdlib/SDL_malloc.c \
+    stdlib/SDL_qsort.c \
+    stdlib/SDL_strtokr.c \
+    video/arm \
+    video/khronos \
+    video/x11/edid-parse.c \
+    video/yuv2rgb
+clang-format -i hidapi/SDL_hidapi.c
+
+# Revert generated code
+git checkout dynapi/SDL_dynapi_overrides.h
+git checkout dynapi/SDL_dynapi_procs.h
+git checkout render/metal/SDL_shaders_metal_*.h
+
+echo "clang-format complete!"