HHH-20737 Add support for batch generation of values

[beikov]

[Please describe here what your change is about]

---

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license
and can be relicensed under the terms of the LGPL v2.1 license in the future at the maintainers' discretion.
For more information on licensing, please check here.

---

---

Please make sure that the following tasks are completed:
Tasks specific to HHH-20737 (Improvement):

• Add tests for feature/improvement
• Update documentation as relevant: javadoc for changed API, documentation/src/main/asciidoc/userguide for all features, documentation/src/main/asciidoc/introduction for main features, links from existing documentation
• Add entries as relevant to migration-guide.adoc (breaking changes) and whats-new.adoc (new features/improvements)

https://hibernate.atlassian.net/browse/HHH-20737

[sonarqubecloud]

Quality Gate failed

Failed conditions
54.0% Coverage on New Code (required ≥ 80%)
C Reliability Rating on New Code (required ≥ A)

See analysis details on SonarQube Cloud

Catch issues before they fail your Quality Gate with our IDE extension SonarQube for IDE

[sebersole]

I find this syntax confusing. It combines multiple arguments on one line and then splits a single argument on another.

Suggested change

	insertMutationPlanner.preInsertInMemoryValueGeneration(
	state, entity, session,
	decompositionContext != null ? decompositionContext.getBatchGenerationContext() : null
	);
	insertMutationPlanner.preInsertInMemoryValueGeneration(
	state,
	entity,
	session,
	decompositionContext != null ? decompositionContext.getBatchGenerationContext() : null
	);

In fact, I'd make this whole statement -

		final boolean hasStateDependentGenerator = insertMutationPlanner.preInsertInMemoryValueGeneration(
				state, 
				entity, 
				session,
				decompositionContext != null ? decompositionContext.getBatchGenerationContext() : null
		);