The Davids are on the case
Only check attributes set by the style guide.

- Default attributes on style guide patterns are not considered requirements
- Additional attributes set in the app that do not conflict with those specified in the style guide do not fail

[Finishes #70889498]
Removed excluded keys logic

The need for this has been removed by rule_based_represention

[#70889498]
Extracted ComputedStylesHash, relevant_attributes
Create ApplicableStyleHash
Refactor representation, split out full_style_representation and relevant_style_representation
increment gem to 0.0.4
Add acceptance test for elements with multiple identical children

[Finishes #67230182]