Adding more e2e tests related to maintenance notifications. Extracting specific tests that validate notifications are received in new connections

[petyaslavova]

Pull Request check-list

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• 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)?

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Description of change

All e2e tests can work with TLS enabled and with TLS disabled - depending on the configuration provided in endpoints_config dictionary.
The same test suite can be executed with both types of setup to validate all use cases with and without TLS.

[Copilot]

Pull Request Overview

This pull request adds comprehensive end-to-end tests for Redis maintenance event notifications during cluster operations. The changes enhance the test suite to validate that notifications are properly received when new connections are established during maintenance states.

• Adds new test cases for failover, migration, and binding operations to validate notification handling
• Extracts specific test scenarios for new connections receiving maintenance events during cluster operations
• Improves timeout handling and error reporting in test infrastructure

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 5 comments.

File	Description
tests/test_scenario/test_hitless_upgrade.py	Main test file with new test cases for failover notifications, connection handling during maintenance states, and improved timeout configurations
tests/test_scenario/hitless_upgrade_helpers.py	Helper functions for failover operations and improved notification waiting with optional timeout failures
tests/test_scenario/fault_injector_client.py	Minor improvements to type hints and error handling
tests/test_scenario/conftest.py	Enhanced client configuration with additional parameters for protocol and host overrides

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