Extract networkstatus_vote_info_t into its own header.

src/or/consdiffmgr.c

@@ -23,6 +23,8 @@
 #include "routerparse.h"
 #include "workqueue.h"
 
+#include "networkstatus_voter_info_st.h"
+
 /**
  * Labels to apply to items in the conscache object.
  *