Simplify and improve order book tracking:

- Avoid using std::shared_ptr
- Prefer using unordered maps to avoid linear searches
- Increase the interval between full order book updates

src/ripple/app/misc/NetworkOPs.cpp

@@ -3072,7 +3072,8 @@ NetworkOPsImp::pubValidatedTransaction(
                 it = mStreamMaps[sRTTransactions].erase(it);
         }
     }
-    app_.getOrderBookDB().processTxn(alAccepted, alTx, jvObj);
+    if (alTx.getResult() == tesSUCCESS)
+        app_.getOrderBookDB().processTxn(alAccepted, alTx, jvObj);
     pubAccountTransaction(alAccepted, alTx, true);
 }