Add entry API overloads that work correctly with nullable value properties

[AndriySvyryd]

This pull request introduces new overloads for the ComplexProperty API in EF Core's change tracking system to support nullable value type complex properties, and updates tests and documentation accordingly. It also includes minor documentation fixes and test improvements for better coverage of optional complex properties.

API enhancements for complex property tracking:

• Added new overloads of ComplexProperty methods in EntityEntry, ComplexPropertyEntry, and ComplexElementEntry classes to support nullable value type (struct?) complex properties, enabling change tracking for optional nested complex properties. [1] [2] [3]

[Copilot]

Pull request overview

This pull request extends EF Core change-tracking entry APIs to better support nullable value-type (struct?) complex properties by adding new ComplexProperty(...) overloads on typed entry types, and updates tests/baselines/docs accordingly.

Changes:

• Added ComplexProperty overloads to EntityEntry<TEntity>, ComplexPropertyEntry<TEntity, TComplexProperty>, and ComplexElementEntry<TEntity, TComplexProperty> for Expression<...TNestedComplexProperty?> with where ... : struct.
• Updated change-tracking and specification tests to include optional/nullable complex properties in coverage and expectations.
• Updated public API baseline and fixed minor documentation text.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
test/EFCore.Tests/ChangeTracking/EntityEntryTest.cs	Adds an optional nullable struct complex property to the model and updates entry/member expectations.
test/EFCore.Specification.Tests/PropertyValuesTestBase.cs	Extends property-values assertions to cover an additional optional complex property path.
test/EFCore.Specification.Tests/NonSharedModelTestBase.cs	Updates the guidance in exception messages thrown when initialization hasn’t occurred.
src/EFCore/Storage/IDatabaseCreator.cs	Fixes a small typo in XML documentation.
src/EFCore/EFCore.baseline.json	Updates API baseline for newly added overload(s).
src/EFCore/ChangeTracking/EntityEntry`.cs	Adds a ComplexProperty overload for nullable value-type complex properties on entity entries.
src/EFCore/ChangeTracking/ComplexPropertyEntry`.cs	Adds a ComplexProperty overload for nullable value-type nested complex properties on complex property entries.
src/EFCore/ChangeTracking/ComplexElementEntry`.cs	Adds a ComplexProperty overload for nullable value-type nested complex properties on complex element entries.

[Copilot]

Pull request overview

Copilot reviewed 8 out of 8 changed files in this pull request and generated no new comments.