Add Arel.sql to pluck fields

Needed to avoid "DEPRECATION WARNING: Dangerous query method..."
See rails/rails#32995

Author: lgebhardt

lib/jsonapi/active_relation_resource_finder.rb

@@ -64,19 +64,19 @@ def find_fragments(filters, options = {})
         records = find_records(filters, options)
 
         table_name = _model_class.table_name
-        pluck_fields = ["#{concat_table_field(table_name, _primary_key)} AS #{table_name}_#{_primary_key}"]
+        pluck_fields = [Arel.sql("#{concat_table_field(table_name, _primary_key)} AS #{table_name}_#{_primary_key}")]
 
         cache_field = attribute_to_model_field(:_cache_field) if options[:cache]
         if cache_field
-          pluck_fields << "#{concat_table_field(table_name, cache_field[:name])} AS #{table_name}_#{cache_field[:name]}"
+          pluck_fields << Arel.sql("#{concat_table_field(table_name, cache_field[:name])} AS #{table_name}_#{cache_field[:name]}")
         end
 
         model_fields = {}
         attributes = options[:attributes]
         attributes.try(:each) do |attribute|
           model_field = attribute_to_model_field(attribute)
           model_fields[attribute] = model_field
-          pluck_fields << "#{concat_table_field(table_name, model_field[:name])} AS #{table_name}_#{model_field[:name]}"
+          pluck_fields << Arel.sql("#{concat_table_field(table_name, model_field[:name])} AS #{table_name}_#{model_field[:name]}")
         end
 
         fragments = {}
@@ -204,21 +204,21 @@ def find_related_monomorphic_fragments(source_rids, relationship, included_key,
         records = related_klass.apply_filters(records, filters, filter_options)
 
         pluck_fields = [
-            "#{primary_key_field} AS #{_table_name}_#{_primary_key}",
-            "#{concat_table_field(table_alias, related_klass._primary_key)} AS #{table_alias}_#{related_klass._primary_key}"
+            Arel.sql("#{primary_key_field} AS #{_table_name}_#{_primary_key}"),
+            Arel.sql("#{concat_table_field(table_alias, related_klass._primary_key)} AS #{table_alias}_#{related_klass._primary_key}")
         ]
 
         cache_field = related_klass.attribute_to_model_field(:_cache_field) if options[:cache]
         if cache_field
-          pluck_fields << "#{concat_table_field(table_alias, cache_field[:name])} AS #{table_alias}_#{cache_field[:name]}"
+          pluck_fields << Arel.sql("#{concat_table_field(table_alias, cache_field[:name])} AS #{table_alias}_#{cache_field[:name]}")
         end
 
         model_fields = {}
         attributes = options[:attributes]
         attributes.try(:each) do |attribute|
           model_field = related_klass.attribute_to_model_field(attribute)
           model_fields[attribute] = model_field
-          pluck_fields << "#{concat_table_field(table_alias, model_field[:name])} AS #{table_alias}_#{model_field[:name]}"
+          pluck_fields << Arel.sql("#{concat_table_field(table_alias, model_field[:name])} AS #{table_alias}_#{model_field[:name]}")
         end
 
         rows = records.pluck(*pluck_fields)
@@ -265,9 +265,9 @@ def find_related_polymorphic_fragments(source_rids, relationship, options = {})
         related_type = concat_table_field(_table_name, relationship.polymorphic_type)
 
         pluck_fields = [
-          "#{primary_key} AS #{_table_name}_#{_primary_key}",
-          "#{related_key} AS #{_table_name}_#{relationship.foreign_key}",
-          "#{related_type} AS #{_table_name}_#{relationship.polymorphic_type}"
+            Arel.sql("#{primary_key} AS #{_table_name}_#{_primary_key}"),
+            Arel.sql("#{related_key} AS #{_table_name}_#{relationship.foreign_key}"),
+            Arel.sql("#{related_type} AS #{_table_name}_#{relationship.polymorphic_type}")
         ]
 
         relations = relationship.polymorphic_relations