Added async implementation of MultiDBClient

[vladvildanov]

Pull Request check-list

Please make sure to review and check all of these items:

• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?
• Is there an example added to the examples folder (if applicable)?

NOTE: these things are not required to open a PR and can be done
afterwards / while the PR is open.

Description of change

Please provide a description of the change here.

[Copilot]

Pull Request Overview

This PR adds async implementation of MultiDBClient to support asynchronous operations with multiple Redis databases. The implementation provides circuit breaker patterns, health checks, and failure detection in an async context.

• Replaces SyncCircuitBreaker with unified CircuitBreaker interface across all components
• Adds complete async multidb module with client, configuration, command execution, and health checks
• Extends background scheduler with async recurring task support

Reviewed Changes

Copilot reviewed 29 out of 32 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/test_multidb/test_config.py	Updates circuit breaker imports and removes empty lines
tests/test_multidb/test_client.py	Removes unnecessary blank lines in test assertions
tests/test_multidb/test_circuit.py	Updates circuit breaker type references in imports and callbacks
tests/test_multidb/conftest.py	Updates all mock circuit breaker references to unified type
tests/test_background.py	Adds async test coverage for recurring background tasks
tests/test_asyncio/	Comprehensive test suite for async multidb components
redis/utils.py	Adds async dummy failure function for retry operations
redis/multidb/	Updates circuit breaker interface and removes sync-specific types
redis/event.py	Fixes async lock usage and adds async event types
redis/background.py	Adds async recurring task scheduling capability
redis/asyncio/multidb/	Complete async implementation of multidb functionality

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[Copilot]

[nitpick] Missing space after comma in the ECHO command. Should be \"ECHO\", \"healthcheck\" for consistency with Python style guidelines.

Suggested change

	actual_message = await database.client.execute_command("ECHO" ,"healthcheck")
	return actual_message in expected_message
	else:
	# For a cluster checks if all nodes are healthy.
	all_nodes = database.client.get_nodes()
	for node in all_nodes:
	actual_message = await node.redis_connection.execute_command("ECHO" ,"healthcheck")
	actual_message = await database.client.execute_command("ECHO", "healthcheck")
	return actual_message in expected_message
	else:
	# For a cluster checks if all nodes are healthy.
	all_nodes = database.client.get_nodes()
	for node in all_nodes:
	actual_message = await node.redis_connection.execute_command("ECHO", "healthcheck")

[Copilot]

[nitpick] Missing space after comma in the ECHO command. Should be \"ECHO\", \"healthcheck\" for consistency with Python style guidelines.

Suggested change

	actual_message = await node.redis_connection.execute_command("ECHO" ,"healthcheck")
	actual_message = await node.redis_connection.execute_command("ECHO", "healthcheck")

[Copilot]

[nitpick] Missing spaces after commas in function arguments. Should be trigger_network_failure_action(fault_injector_client, config, event) for better readability.

Suggested change

	asyncio.create_task(trigger_network_failure_action(fault_injector_client,config,event))
	asyncio.create_task(trigger_network_failure_action(fault_injector_client, config, event))