Backport ACL computation improvements

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/common/utils.py

@@ -33,6 +33,26 @@ def encapsulate(function):
     return lambda: function
 
 
+def get_related_field(model, related_field_name):
+    try:
+        local_field_name, remaining_field_path = related_field_name.split(
+            LOOKUP_SEP, 1
+        )
+    except ValueError:
+        local_field_name = related_field_name
+        remaining_field_path = None
+
+    related_field = model._meta.get_field(local_field_name)
+
+    if remaining_field_path:
+        return get_related_field(
+            model=related_field.related_model,
+            related_field_name=remaining_field_path
+        )
+
+    return related_field
+
+
 def introspect_attribute(attribute_name, obj):
     """
     Resolve the attribute of model. Supports nested reference using dotted