REORG: include: move arg.h to haproxy/arg{,-t}.h

Almost no change was needed; chunk.h was replaced with buf-t.h.
It dpeends on types/vars.h and types/protocol_buffers.h.
diff --git a/src/tcp_rules.c b/src/tcp_rules.c
index d6c1eb3..262224d 100644
--- a/src/tcp_rules.c
+++ b/src/tcp_rules.c
@@ -17,7 +17,7 @@
 #include <haproxy/ticks.h>
 #include <haproxy/time.h>
 
-#include <types/arg.h>
+#include <haproxy/arg-t.h>
 #include <types/capture.h>
 #include <types/connection.h>
 #include <types/global.h>