Add Listener for Configurable Alert Timeout

[cvillarongace]

Description

This PR introduces a new feature to dynamically update the alert timeout based on configuration changes. The feature enhances the reactivity of the MessageService by subscribing to changes in the configuration observable stream, specifically monitoring the alert_timeout property in the UI configuration.

Motivation and Context

The motivation for this change stems from a timing issue where the configuration was being loaded before the user-defined settings were properly applied. This resulted in the alert_timeout value defaulting to 3 seconds, regardless of the value specified in extensions or user settings. By introducing a listener for configuration changes, this update ensures that the alert timeout dynamically reflects the correct value as configured by the user, improving alignment between the application behavior and user expectations.

Benefits:

• Dynamic Updates: Alert timeout adjusts automatically based on configuration changes.
• Improved UX: Allows for more flexible and responsive user interface customization.
• Efficiency: Avoids unnecessary updates using distinctUntilChanged.

Notes:

-This change is backward-compatible. If no alert_timeout is specified, the default value remains intact.
-Documentation for this enhancement has been included in the method comments.

How To Test This

• Verified that MessageService reacts to changes in SystemConfigStore.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• [ x] New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Final checklist

• [ x] My code follows the code style of this project found here.
• My change requires a change to the documentation.
• [ x] I have read the How to Contribute guidelines.

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[desarrollador20]

the code works correctly