Add CI workflow to check line endings of all source files (#2082)

In addition, all found errors (formatting & line ending) have been fixed in this PR.

tools/check-format.sh

@@ -4,12 +4,14 @@ set -eu
 
 fail="0"
 
+clang-format --version
+
 while read -r file; do
     if ! diff -u <(cat "$file") <(clang-format "$file"); then
         echo "$file differs!!!!!!!"
         fail="1"
     fi
-done < <(find src/ \( -iname "*.hpp" -o -iname "*.cpp" \))
+done < <(find src/ -type f \( -iname "*.hpp" -o -iname "*.cpp" \))
 
 if [ "$fail" = "1" ]; then
     echo "At least one file is poorly formatted - check the output above"