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

This one is particularly difficult to split because it provides all the
functions used to manipulate a proxy state and to retrieve names or IDs
for error reporting, and as such, it was included in 73 files (down to
68 after cleanup). It would deserve a small cleanup though the cut points
are not obvious at the moment given the number of structs involved in
the struct proxy itself.
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 63624f6..c2a1869 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -40,6 +40,7 @@
 #include <haproxy/list.h>
 #include <haproxy/listener.h>
 #include <haproxy/log.h>
+#include <haproxy/proxy-t.h>
 #include <haproxy/sample.h>
 #include <haproxy/tools.h>
 #include <haproxy/namespace.h>
@@ -51,7 +52,6 @@
 #include <haproxy/port_range.h>
 #include <haproxy/protocol.h>
 #include <haproxy/proto_tcp.h>
-#include <proto/proxy.h>
 #include <proto/server.h>
 #include <haproxy/tcp_rules.h>