REORG: include: move common/chunk.h to haproxy/chunk.h

No change was necessary, it was already properly split.
diff --git a/src/http_fetch.c b/src/http_fetch.c
index c253c8d..8fe22b8 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -18,7 +18,7 @@
 
 #include <haproxy/api.h>
 #include <haproxy/base64.h>
-#include <common/chunk.h>
+#include <haproxy/chunk.h>
 #include <common/h1.h>
 #include <common/http.h>
 #include <common/htx.h>