Add advanced email filtering features: catch-all, plus-addressing, and pattern forwarding

Features:
- Catch-All Email: Forward unmatched emails for a domain to a single address
- Plus-Addressing: Enable user+tag@domain.com delivery with configurable delimiter
- Pattern Forwarding: Wildcard and regex-based email forwarding rules

Implementation:
- New database models: CatchAllEmail, EmailServerSettings, PlusAddressingOverride, PatternForwarding
- New UI pages with AngularJS controllers
- Backend methods in mailserverManager.py with ACL permission checks
- Auto-generates /etc/postfix/virtual_regexp for pattern rules
- Menu items added under Email section

baseTemplate/templates/baseTemplate/index.html

@@ -1573,6 +1573,21 @@
                     <span>Email Forwarding</span>
                 </a>
                 {% endif %}
+                {% if admin or emailForwarding %}
+                <a href="{% url 'catchAllEmail' %}" class="menu-item">
+                    <span>Catch-All Email</span>
+                </a>
+                {% endif %}
+                {% if admin or emailForwarding %}
+                <a href="{% url 'patternForwarding' %}" class="menu-item">
+                    <span>Pattern Forwarding</span>
+                </a>
+                {% endif %}
+                {% if admin %}
+                <a href="{% url 'plusAddressingSettings' %}" class="menu-item">
+                    <span>Plus-Addressing</span>
+                </a>
+                {% endif %}
                 {% if admin or changeEmailPassword %}
                 <a href="{% url 'changeEmailAccountPassword' %}" class="menu-item">
                     <span>Change Password</span>