Background: the transform node from world to tangent had to be fixed, as it used an algorithm that assumed that the tangent space basis was always orthonormal, which is not always the case. The view direction node, when in tangent space, used the same algorithm as the transform node used to, and hasn't been updated.

Repro steps:
1. Open the attached shadergraph in Universal RP
Expected result: the preview is solid black
Actual result: the preview has color in between the vertices, indicating that the View Direction in tangent space, when transformed to world space, does not exactly match the View Direction in world space (normalized).

Documentation ticket: https://unity3d.atlassian.net/browse/DOC-2825

Relates to https://fogbugz.unity3d.com/f/cases/edit/1217639/