[ticket/14041] Add viewtopic_dropdown_*_custom template event

Allows an extension to create a custom dropdown menu.

PHPBB3-14041
PHPBB3-14042

phpBB/styles/prosilver/template/viewtopic_body.html

@@ -40,6 +40,7 @@
 	</div>
 
 	<!-- INCLUDE viewtopic_topic_tools.html -->
+	<!-- EVENT viewtopic_dropdown_top_custom -->
 
 	<!-- IF S_DISPLAY_SEARCHBOX -->
 		<div class="search-box" role="search">
@@ -375,6 +376,8 @@
 			</div>
 		</div>
 	<!-- ENDIF -->
+	
+	<!-- EVENT viewtopic_dropdown_bottom_custom -->
 
 	<!-- IF .pagination or TOTAL_POSTS -->
 		<div class="pagination">