Make NodeViewCustomization tests less flaky

### Purpose

A couple of the `NodeViewCustomization` tests have proven themselves to be flaky when run by the CI.  Specifically, the tests using `UnitsUI` or `IronPythonUI` have fail because the `NodeView` could not be located for the specified `NodeModel` type.

This is odd, as the `NodeModel` is clearly in the file.  Further, this failure only happens occasionally.  In other words, it is very difficult for me to track down the origin of this failure.

### Possible reason

I have run into this kind of behavior before then the same `Type` has for some reason been loaded  multiple times into the same app when there are multiple copies of the same assembly present in the build directory.  This might happen because of erroneous copy local flag on an Assembly Reference.

### Fix

I've fixed what appear to be a large number of erroneous `Copy Local` flags in VMDataBridge and DynamoCoreUITests.

However, the major fix I've implemented is to just not use these types at all in `NodeViewCustomizationTests` by looking up the nodes by GUID.  These tests will never fail by the mechanism mentioned above.

### Reviewers

@ikeough 

CC: @RodRecker