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

Almost no changes, removed stdlib and added buf-t and connection-t to
the types to avoid a warning.
diff --git a/src/ssl_ckch.c b/src/ssl_ckch.c
index d0699ef..f971bee 100644
--- a/src/ssl_ckch.c
+++ b/src/ssl_ckch.c
@@ -27,12 +27,12 @@
 #include <haproxy/ssl_ckch.h>
 #include <haproxy/ssl_sock.h>
 #include <haproxy/ssl_utils.h>
+#include <haproxy/stream_interface.h>
 #include <haproxy/tools.h>
 
 #include <import/ebsttree.h>
 
 #include <proto/channel.h>
-#include <proto/stream_interface.h>
 
 /* Uncommitted CKCH transaction */