Refactor tag fieldsets in DealAdmin

Updated the DealAdmin configuration to use the new `get_tag_fieldsets` method for managing tag-related fields. This change improves code modularity and reduces redundancy in the `dealadmin.py` file.

Author: Vadym-Kharchenko

crm/site/dealadmin.py

@@ -264,10 +264,7 @@ def get_fieldsets(self, request, obj=None):
             (' ', {
                 'fields': ('tag_list',)
             }),
-            (_('Add tags'), {
-                'classes': ('collapse',),
-                'fields': ('tags',)
-            }),
+            *self.get_tag_fieldsets(obj),
             (_('Relations'), {
                 'classes': ('collapse',),
                 'fields': (