REORG: tcp-rules: move tcp rules processing to their own file

There's no more reason to keep tcp rules processing inside proto_tcp.c
given that there is nothing in common there except these 3 letters : tcp.
The tcp rules are in fact connection, session and content processing rules.
Let's move them to "tcp-rules" and let them live their life there.
diff --git a/src/stream.c b/src/stream.c
index 21d12e7..0f84834 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -57,6 +57,7 @@
 #include <proto/stick_table.h>
 #include <proto/stream_interface.h>
 #include <proto/task.h>
+#include <proto/tcp_rules.h>
 #include <proto/vars.h>
 
 struct pool_head *pool2_stream;