fix(oas3): switching media types should update schema properties

[tim-lai]

Description

• When the media-type is changed, there is a new onChangeMediaType method to handle actions.
• If target schema properties key/value pairs does NOT equals current schema properties, clear the requestBodyValue, tyr-it-out request/response and validation params.
• If target schema properties key/value pairs DOES equals current schema properties, do not change or re-render schema properties
• oas3Selector validateShallowRequired now also validates required keys against target media-type

Motivation and Context

Each media-type can have its own schema.

Fixes #6201
Fixes #6250
Fixes #6476

How Has This Been Tested?

New Jest test for reducer CLEAR_REQUEST_BODY_VALUE
New Cypress tests includes checking for undesired artifacts in Try-It-Out cURL command, and implicitly confirms that existing validation rules still apply.

Screenshots (if appropriate):

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

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• My changes require a change to the project documentation.
• If yes to above: I have updated the documentation accordingly.

Automated tests

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• 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.