Make Clio RPCs more consistent with rippled (#110)

* parse ledger_index as number

* allow websocket to use "command" or "method"

* mark all non-forwarded responses as validated

* dont mark forwarded errors as successful

* reduce forwarding Websocket expiration 30->3 seconds

* fix merge conflict in test.py

* adds ledger_current and ledger_closed

* deserialize `taker_gets_funded` into amount json

* limit account RPCs by number of objects traversed

* assign result correctly

src/rpc/Counters.cpp

@@ -1,4 +1,5 @@
 #include <rpc/Counters.h>
+#include <rpc/RPC.h>
 
 namespace RPC {
 
@@ -19,6 +20,9 @@ Counters::initializeCounter(std::string const& method)
 void
 Counters::rpcErrored(std::string const& method)
 {
+    if (!validHandler(method))
+        return;
+
     initializeCounter(method);
 
     std::shared_lock lk(mutex_);
@@ -32,6 +36,9 @@ Counters::rpcComplete(
     std::string const& method,
     std::chrono::microseconds const& rpcDuration)
 {
+    if (!validHandler(method))
+        return;
+
     initializeCounter(method);
 
     std::shared_lock lk(mutex_);
@@ -44,6 +51,9 @@ Counters::rpcComplete(
 void
 Counters::rpcForwarded(std::string const& method)
 {
+    if (!validHandler(method))
+        return;
+
     initializeCounter(method);
 
     std::shared_lock lk(mutex_);