Make testing_quorum JSON serialization work for input

The block explorer uses loki's KV serialization structs for its RPC
commands, but testing_quorum was only doing outbound serialization of
validators/workers.  This adds the missing inbound serialization code.

src/cryptonote_core/service_node_quorum_cop.h

@@ -57,13 +57,29 @@ namespace service_nodes
     END_SERIALIZE()
 
     BEGIN_KV_SERIALIZE_MAP()
-      std::vector<std::string> validators(this_ref.validators.size());
-      for (size_t i = 0; i < this_ref.validators.size(); i++) validators[i] = epee::string_tools::pod_to_hex(this_ref.validators[i]);
-      KV_SERIALIZE_VALUE(validators);
+      std::vector<std::string> validators, workers;
+      if (is_store)
+      {
+        validators.reserve(this_ref.validators.size());
+        workers.reserve(this_ref.workers.size());
+        for (auto &v : this_ref.validators)
+          validators.push_back(epee::string_tools::pod_to_hex(v));
+        for (auto &w : this_ref.workers)
+          workers.push_back(epee::string_tools::pod_to_hex(w));
+      }
 
-      std::vector<std::string> workers(this_ref.workers.size());
-      for (size_t i = 0; i < this_ref.workers.size(); i++) workers[i] = epee::string_tools::pod_to_hex(this_ref.workers[i]);
+      KV_SERIALIZE_VALUE(validators);
       KV_SERIALIZE_VALUE(workers);
+
+      if (!is_store)
+      {
+        this_ref.validators.resize(validators.size());
+        this_ref.workers.resize(workers.size());
+        for (size_t i = 0; i < validators.size(); i++)
+          epee::string_tools::hex_to_pod(validators[i], this_ref.validators[i]);
+        for (size_t i = 0; i < workers.size(); i++)
+          epee::string_tools::hex_to_pod(workers[i], this_ref.workers[i]);
+      }
     END_KV_SERIALIZE_MAP()
   };