Added support for a delegating data loader

[bbakerman]

This allows you to more easily wrap a DataLoader.

This uses the wonderful parameterised test factories and hence ALL the current (and future) data loader tests will run with the delegation in place.

This REALLY REALLY proves the delegation works and will continue to work for new tests

[Copilot]

Pull Request Overview

This PR introduces support for a delegating DataLoader, making it easier to wrap and extend DataLoader behavior while ensuring that all existing and future tests run with delegation in place. Key changes include:

• Adding an unwrap method to the TestDataLoaderFactory interface.
• Introducing a new DelegatingDataLoaderFactory class along with parameterized tests using delegated factories.
• Implementing a DelegatingDataLoader and updating tests and core DataLoader methods to use the unwrap functionality.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/test/java/org/dataloader/fixtures/parameterized/TestDataLoaderFactory.java	Added unwrap() method to support loader delegation
src/test/java/org/dataloader/fixtures/parameterized/TestDataLoaderFactories.java	Extended tests to run via delegating DataLoader factories
src/test/java/org/dataloader/fixtures/parameterized/DelegatingDataLoaderFactory.java	New class implementing a delegating DataLoader factory
src/test/java/org/dataloader/DelegatingDataLoaderTest.java	Added tests to verify unwrapping and delegation behavior
src/test/java/org/dataloader/DataLoaderTest.java	Updated type-check conditions to use unwrap()
src/main/java/org/dataloader/DelegatingDataLoader.java	Introduced a delegating wrapper for DataLoader
src/main/java/org/dataloader/DataLoader.java	Added parameter annotations and a null check in load()

Comments suppressed due to low confidence (1)

src/test/java/org/dataloader/fixtures/parameterized/DelegatingDataLoaderFactory.java:13

• [nitpick] Consider rephrasing this comment for clarity and professionalism, e.g., 'It delegates to the underlying DataLoader instance.'

    // its delegates all the way down to the turtles