ST6RI-719 View rendering redefinition is incorrect

[seidewitz]

1. This PR corrects the implicit redefinition of a RenderingUsage that is a view rendering of a ViewDefinition or ViewUsage (i.e., that is owned via a ViewRenderingMembership). Previously, the implemented gave a view rendering implicit redefinitions of the view renderings of any view definitions or usages specialized by the containing view definition or usage. This has now been changed to conform to the SysML v2 Specification, which requires that view rendering directly redefine Views::View::viewRendering.
2. The PR also corrects the checking of the validateViewDefinitionOnlyOneViewRendering and validateViewUsageOnlyOneViewRendering, so that a ViewDefinition or ViewUsage can have owned RedefinitionUsages other than its (at most) one view rendering.