Feature: debug message for loaded ServerAlias directives

[this-is-varunxyz]

Description- Currently, when the CUPS scheduler loads a ServerAlias directive from the cupsd.conf file, it does not produce a debug message. This can lead to confusion, as users may think their ServerAlias is being ignored.

This was originally discussed in issue #1374,

Proposed Solution- This feature request proposes adding a debug-level log message that fires every time a ServerAlias is successfully added from the configuration file.

The change involves adding a single cupsdLogMessage() call in scheduler/conf.c immediately after an alias is added.

Benefits- Reduces User Confusion: Prevents users from incorrectly assuming ServerAlias is broken, as seen in the original issue.