netinfo: add ConnectionTypeForNetinfo member helper function

src/bitcoin-cli.cpp

@@ -351,6 +351,14 @@ private:
         const double milliseconds{round(1000 * seconds)};
         return milliseconds > 999999 ? "-" : ToString(milliseconds);
     }
+    std::string ConnectionTypeForNetinfo(const std::string& conn_type) const
+    {
+        if (conn_type == "outbound-full-relay") return "full";
+        if (conn_type == "block-relay-only") return "block";
+        if (conn_type == "manual" || conn_type == "feeler") return conn_type;
+        if (conn_type == "addr-fetch") return "addr";
+        return "";
+    }
     const UniValue NetinfoHelp()
     {
         return std::string{