Added support for save integral term parameter

Added save_iterm parameter
Added check for default false in tests

Applied suggestions from code review

More comment updates

Author: Whalex451

pid_controller/src/pid_controller.yaml

@@ -74,6 +74,11 @@ pid_controller:
         default_value: 0.0,
         description: "Lower integral clamp. Only used if antiwindup is activated."
       }
+      save_iterm: {
+        type: bool,
+        default_value: false,
+        description: "Enables save of integral term on pid reset. Integrator error will not be set to 0.  This is useful for pid loops that are enabled/disabled with constant steady-state external disturbance."
+      }
       feedforward_gain: {
         type: double,
         default_value: 0.0,

pid_controller/test/test_pid_controller.cpp

@@ -52,6 +52,7 @@ TEST_F(PidControllerTest, all_parameters_set_configure_success)
     ASSERT_FALSE(controller_->params_.gains.dof_names_map[dof_name].antiwindup);
     ASSERT_EQ(controller_->params_.gains.dof_names_map[dof_name].i_clamp_max, 5.0);
     ASSERT_EQ(controller_->params_.gains.dof_names_map[dof_name].i_clamp_min, -5.0);
+    ASSERT_FALSE(controller_->params_.gains.dof_names_map[dof_name].save_iterm);
     ASSERT_EQ(controller_->params_.gains.dof_names_map[dof_name].feedforward_gain, 0.0);
   }
   ASSERT_EQ(controller_->params_.command_interface, command_interface_);