all: more cleanups

Changes include:
  - extract headers.h from conf.h
  - use "byte" in some more places
  - unify "const" coding style
  - pefile.cpp: make sort order deterministic
  - simplify some other pefile.cpp code
  - CI updates

src/msg.cpp

@@ -25,6 +25,8 @@
    <markus@oberhumer.com>               <ezerotven+github@gmail.com>
  */
 
+#include "headers.h"
+#include <typeinfo>
 #include "conf.h"
 
 /*************************************************************************