lots of cleanup and simplification in test case construction

@miSim/teardown.m

@@ -0,0 +1,13 @@
+function teardown(obj)
+    arguments (Input)
+        obj (1, 1) {mustBeA(obj, 'miSim')};
+    end
+    arguments (Output)
+    end
+
+    % Close plots
+    close(obj.hf);
+    close(obj.fPerf);
+    close(obj.f);
+
+end