Add fpc_ProcID type and use it for all process IDs

See https://github.com/zeldaret/tp/pull/2173

src/d/d_event_data.cpp

@@ -270,7 +270,7 @@ void dEvDtStaff_c::specialProcMessage() {
         "TELOP_ON",
         "TELOP_OFF",
     };
-    static uint l_msgId;
+    static fpc_ProcID l_msgId;
     static msg_class* l_msg;
     static int l_msgNo;