Add verification scripts for clang-format

The scripts are very light on error handling and verification, mostly
intended just to debug if a CI server fails on formatting reasons.

build_scripts/win/verify_formatting.cmd

@@ -0,0 +1,9 @@
+@echo off
+REM Arg 0 (called %0) is the full path to the file.
+REM https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/call#batch-parameters
+REM As per above link, %~dp0 expands the zeroth arg to a drive letter and path only.
+REM Project dir is up two dirs from the file.
+SET project_dir=%~dp0\..\..\
+
+python %project_dir%/build_scripts/run-clang-format.py %project_dir%/src -r --color never --clang-format-executable %CLANG_FORMAT_LOC%
+IF NOT ERRORLEVEL 1 THEN ECHO FORMATTED CORRECTLY.