Layout differencing across variants compared in props, modes

[nathanacurtis]

Problem

Differences in autolayout aren't compared during comparisons that generate Properties and Modes outputs. However, there's often considerable meaningful layout variation.

Including layout variations in the Props and Modes sections isn' practical. Layout is hierarchical and requires multiple artwork frames, and each variant is represented by one – and only one – artwork frame.

Solution

Detect differences during Props and Modes comparisons.
Show differences as additional subsections in Layout and spacing.
Name which variant(s) do and don't include the layer with a autolayout configuration that was differenced.

[nathanacurtis]

Duplicates #103