[automatic-failover] Improve extensibility that is needed for automatic-failover feature

[atakavci]

This PR introduces a new Delegating<T> interface and refactors RedisClient to support better extensibility.

New Delegating<T> Interface

Added a generic interface for classes that wrap/delegate to another object

Updated Wrapper Classes

CommandListenerWriter now implements Delegating<RedisChannelWriter>
CommandExpiryWriter now implements Delegating<RedisChannelWriter>

RedisClient Extensibility

• Added protected factory methods:
  • createEndpoint() - Creates DefaultEndpoint instances
  • createPubSubEndpoint() - Creates PubSubEndpoint instances
• Replaced direct new DefaultEndpoint() calls with factory method calls
• Allows subclasses to customize endpoint creation behavior

[Copilot]

Pull Request Overview

This PR introduces a generic Delegating<T> interface to enable consistent unwrapping of delegating wrappers in the codebase. The main changes include:

• Added a new Delegating<T> interface with getDelegate() and unwrap() methods for recursive unwrapping
• Updated CommandExpiryWriter and CommandListenerWriter to implement the Delegating<RedisChannelWriter> interface
• Refactored RedisClient to use factory methods (createEndpoint() and createPubSubEndpoint()) for better extensibility
• Fixed a redundant cast in NodeSelectionInvocationHandler for the reactive executions path

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
Delegating.java	New interface providing a standard way to access and recursively unwrap delegates
CommandExpiryWriter.java	Implements Delegating<RedisChannelWriter> to enable generic unwrapping
CommandListenerWriter.java	Implements Delegating<RedisChannelWriter> to enable generic unwrapping
RedisClient.java	Extracted endpoint creation into protected factory methods for subclass customization
NodeSelectionInvocationHandler.java	Removed redundant cast when creating ReactiveExecutionsImpl

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[Copilot]

The double cast pattern (Map) reactiveExecutions where reactiveExecutions is already cast on line 180 is redundant. While this change removes one level of casting, there's still an unchecked cast being performed. Consider whether the ReactiveExecutionsImpl constructor signature can be updated to accept Map<RedisClusterNode, CompletionStage<? extends Publisher<?>>> directly to eliminate the need for unsafe casts.

Suggested change

	return new ReactiveExecutionsImpl<>((Map) reactiveExecutions);
	return new ReactiveExecutionsImpl<>(reactiveExecutions);