fix: nested example references not resolved when path parameter in reference chain

[jhemelhof]

Pull Request

Description

Fixes: #2244

The second parameter of processRefExample is the "externalFile" but current implementation provided the reference, which isn't correct. That behavior is now fixed with this PR and aligns with what's done for processRefSchemaObject.

Type of Change

• [x] 🐛 Bug fix

Checklist

• [x] I have added/updated tests as needed
• [ ] I have added/updated documentation where applicable
• [x] The PR title is descriptive
• [x] The code builds and passes tests locally
• [x] I have linked related issues (if any)