Resolver regression (WIP)

[shockey]

Description

This PR will (eventually) solve a rather specific resolver regression introduced last Friday.

what I know....

• This line in this PR is creating (indirectly at least) a patch against a nonexistent path...
• which is causing the [p] property access here to fail during the patchValueAlreadyInPath check here.
• The order of the keys in the document affect the outcome: sorting referenced objects low-to-high (definitions before paths, definitions in order of DataModifier, DataModifiers, DataObject, DataObjectArray) will resolve correctly.
• The issue seems to be unique to this sample: switching the order of definitions and paths in Petstore, for example, does not appear to cause any issues.

Motivation and Context

Fixes swagger-api/swagger-editor#1661.

How Has This Been Tested?

Unit test added.

Types of changes

• No code changes (changes to documentation, CI, metadata, etc)
• Dependency changes (any modification to dependencies in package.json)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.