Allow Filtering of Anonymous Contacts in Segment Counts

Hello Mautic Team,

Description:
Currently, in Mautic 6, segment counts include both known and anonymous contacts. This can make it difficult to accurately understand and target specific audiences, as anonymous contacts are mixed with tracked leads who have identifiable information.

Feature Request:
Introduce the ability to detect anonymous contacts and create segment filter rules that allow:

* Excluding anonymous contacts from a segment count or segment actions.
* Including only anonymous contacts in a segment if needed for specific campaigns.

This could be implemented as a new filter condition in the segment builder, e.g., `Contact is Anonymous` with `Yes/No` options.

Benefits:
* Provides more accurate segment counts and reporting.
* Enables marketers to tailor campaigns to known leads while managing anonymous visitors separately.
* Improves segmentation flexibility and overall marketing automation strategy.

Optional Enhancements:
* Display a distinct label or icon for anonymous contacts in segment lists.
* Allow combining this filter with other segment conditions (e.g., location, tags, campaign activity).

Thank you for considering this improvement and for your continued work on making Mautic more flexible and user-friendly.