Magn491

#### Background
The connectors are not updated during an undo/redo operation due to a [recent change](https://github.com/ikeough/Dynamo/commit/6625f6b766ea524bc5ff3b007af0219942782259) in the way Connectors react to their ports. The connectors no longer redraw themselves when an undo/redo operation updated the position of a node. This is now fixed with an additional call to "NodeModel.ReportPosition" method, which in turn notifies the attached connectors.

#### Unit Testing
* Added a failing test case "Defect_MAGN_491" to verify the fix (which now passes with the fix).

* Passed unit tests: DSCoreNodesTests, DynamoMSOfficeTests, DynamoCoreTests, DynamoCoreUITests, DynamoPythonTests.