Fix 6372: Updating server select prop and test

[ben-smartbear]

This PR fixes the prop error generated by React introduced in #6358. Fixes #6372.

Description

Changes the currentServer value to be assigned at the top of the select instead of as a selected prop on the option.

Motivation and Context

This fixes the React warning introduced in #6358.

How Has This Been Tested?

Automation was tweaked to fix for this. Tested on local installation with multiple openapi 3 specs.

Checklist

My PR contains...

• No code changes (src/ is unmodified: changes to documentation, CI, metadata, etc.)
• Dependency changes (any modification to dependencies in package.json)
• Bug fixes (non-breaking change which fixes an issue)
• Improvements (misc. changes to existing features)
• Features (non-breaking change which adds functionality)

My changes...

• are breaking changes to a public API (config options, System API, major UI change, etc).
• are breaking changes to a private API (Redux, component props, utility functions, etc.).
• are breaking changes to a developer API (npm script behavior changes, new dev system dependencies, etc).
• are not breaking changes.

Documentation

• My changes do not require a change to the project documentation.
• My changes require a change to the project documentation.
• If yes to above: I have updated the documentation accordingly.

Automated tests

• My changes can not or do not need to be tested.
• My changes can and should be tested by unit and/or integration tests.
• If yes to above: I have added tests to cover my changes.
• If yes to above: I have taken care to cover edge cases in my tests.
• All new and existing tests passed.

[tim-lai]

@ben-smartbear Merged! Thanks for the refactor.