…tegory method.

The popover and terminal tests also use generic views but cannot leverage the
category method because they require a reference to the label that's part of the
generic view. Nevertheless, their layout of the label has been updated to fix a
clipping issue discovered in the development of the category method.

…presentation.

…ions directly.

As opposed to calling functions using the methods defined in
the `ConvenienceFunctions` category.

…LGeometry.h`.

And add a missing test for `SLUIARectFromCGRect`.