REORG: include: move activity to haproxy/

This moves types/activity.h to haproxy/activity-t.h and
proto/activity.h to haproxy/activity.h.

The macros defining the bit field values for the profiling variable
were moved to the type file to be more future-proof.
diff --git a/include/proto/fd.h b/include/proto/fd.h
index f882b54..2d45e06 100644
--- a/include/proto/fd.h
+++ b/include/proto/fd.h
@@ -31,7 +31,7 @@
 #include <common/ticks.h>
 #include <haproxy/time.h>
 #include <types/fd.h>
-#include <proto/activity.h>
+#include <haproxy/activity.h>
 
 /* public variables */