Fix data field for loaded program RobotAPI call (#443)

When implementing the RobotAPI 3.1.4 the get_loaded_program call did not
implement the data field correctly matching the
[documentation](https://github.com/UniversalRobots/Universal_Robots_Client_Library/blob/542731ab3bd4d0e06ab7b91fc733ec36cb5af150/include/ur_client_library/ur/dashboard_client.h#L517)
and the [G5
implementation](https://github.com/UniversalRobots/Universal_Robots_Client_Library/blob/542731ab3bd4d0e06ab7b91fc733ec36cb5af150/src/ur/dashboard_client_implementation_g5.cpp#L937).
This commit fixes that.

Author: urfeex

src/ur/dashboard_client_implementation_x.cpp

@@ -304,7 +304,7 @@ DashboardResponse DashboardClientImplX::commandGetLoadedProgram()
   auto json_data = json::parse(response.message);
   if (response.ok)
   {
-    response.data["loaded_program"] = std::string(json_data["name"]);
+    response.data["program_name"] = std::string(json_data["name"]);
   }
   return response;
 }

tests/test_dashboard_client_x.cpp

@@ -119,7 +119,7 @@ TEST_F(DashboardClientTestX, get_loaded_program)
   {
     auto response = dashboard_client_->commandGetLoadedProgram();
     ASSERT_TRUE(response.ok);
-    ASSERT_EQ(std::get<std::string>(response.data["loaded_program"]), "Default program");
+    ASSERT_EQ(std::get<std::string>(response.data["program_name"]), "Default program");
   }
 }
 
@@ -200,7 +200,7 @@ TEST_F(DashboardClientTestX, program_interaction)
   if (dashboard_client_->getRobotApiVersion() >= VersionInformation::fromString("3.1.4"))
   {
     response = dashboard_client_->commandGetLoadedProgram();
-    ASSERT_EQ(std::get<std::string>(response.data["loaded_program"]), "wait_program");
+    ASSERT_EQ(std::get<std::string>(response.data["program_name"]), "wait_program");
   }
   response = dashboard_client_->commandPowerOn();
   ASSERT_TRUE(response.ok);