Add Cisco Unified Communications templates

[DevYves89]

Summary

Adds two Zabbix 7.0 community templates for Cisco Collaboration:

• Cisco Unified Communications Manager 15 by API
• Cisco Unity Connection 15 by API

Contents

• Versioned 7.0 YAML export and README for each template under Telephony/PBX.
• Documented macro setup, least-privilege access requirements, metrics, alerts, and limitations.
• Full-HD overview dashboards, documented raw/master retention, operator/internal item tags, and safe HTTP proxy macros.

Validation

• Static CUCM validation plus CUC preprocessing/fixture validations passed.
• Both public exports imported and re-exported on Zabbix 7.0.
• Both templates were linked to representative lab hosts; fresh core operator items and zero unsupported items were confirmed.

Scope

This PR contains only the two public template version folders (one YAML export and one README per template). It contains no lab fixtures, hosts, logs, endpoint addresses, or credential values.