NetconfAccess: Use <edit-data> instead of <edit-config>

We're already using <get-data>, so it makes sense to do this. It also
makes it easier to work with datastores, because it uses the NMDA
datastores.

Change-Id: Ie4d5acdf45e1394ea3c0c0398384e855a53b4500
diff --git a/src/netconf-client.hpp b/src/netconf-client.hpp
index 0794958..839c528 100644
--- a/src/netconf-client.hpp
+++ b/src/netconf-client.hpp
@@ -20,6 +20,7 @@
 enum class NmdaDatastore {
     Startup,
     Running,
+    Candidate,
     Operational
 };
 namespace client {
@@ -55,6 +56,7 @@
                     const NC_RPC_EDIT_TESTOPT testOption,
                     const NC_RPC_EDIT_ERROPT errorOption,
                     const std::string& data);
+    void editData(const NmdaDatastore datastore, const std::string& data);
     void copyConfigFromString(const NC_DATASTORE target, const std::string& data);
     std::shared_ptr<libyang::Data_Node> rpc_or_action(const std::string& xmlData);
     void copyConfig(const NC_DATASTORE source, const NC_DATASTORE destination);