Make javabean field private

[bernardnormier]

This PR updates the JavaBean-style mapping field to be private, just like for optional fields.

[Copilot]

Pull Request Overview

This PR makes JavaBean-style mapping fields private to maintain consistency with optional fields. The change ensures that both optional fields and JavaBean fields (with getter/setter methods) follow the same encapsulation pattern by being declared as private instead of public.

• Updates field visibility logic to include JavaBean-style fields alongside optional fields
• Maintains consistent encapsulation patterns across different field types

[Copilot]

[nitpick] The condition combines two different concepts (getSet and isOptional) without clear documentation. Consider adding a comment explaining why both JavaBean fields and optional fields should be private, or extract this logic into a well-named boolean variable like 'shouldBePrivate' for better readability.

Suggested change

	if (getSet || isOptional)
	// Fields should be private if they are JavaBean properties (getSet) or optional fields (isOptional),
	// to ensure encapsulation for getter/setter methods and to manage presence tracking for optionals.
	const bool shouldBePrivate = getSet || isOptional;
	if (shouldBePrivate)

[InsertCreativityHere]

Looks good to me!