Report server versions when crawling the overlay network

src/ripple/overlay/impl/OverlayImpl.cpp

@@ -632,6 +632,9 @@ OverlayImpl::crawl()
                 else
                     pv[jss::ip] = sp->getRemoteAddress().to_string();
             }
+            auto version = sp->getVersion ();
+            if (!version.empty ())
+                pv["version"] = version;
         }
     }
     return jv;

src/ripple/overlay/impl/PeerImp.cpp

@@ -197,6 +197,15 @@ PeerImp::crawl() const
     return beast::ci_equal(iter->second, "public");
 }
 
+std::string
+PeerImp::getVersion() const
+{
+    if (hello_.has_fullversion ())
+        return hello_.fullversion ();
+
+    return std::string ();
+}
+
 Json::Value
 PeerImp::json()
 {

src/ripple/overlay/impl/PeerImp.h

@@ -237,6 +237,10 @@ public:
         return publicKey_;
     }
 
+    /** Return the version of rippled that the peer is running, if reported. */
+    std::string
+    getVersion() const;
+
     Json::Value
     json() override;