Integrate new stages into ci pipeline serializer

app/serializers/pipeline_entity.rb

@@ -15,7 +15,7 @@ class PipelineEntity < Grape::Entity
     expose :detailed_status, as: :status, using: StatusEntity
     expose :duration
     expose :finished_at
-    expose :stages_with_statuses, as: :stages, using: PipelineStageEntity
+    expose :stages, using: PipelineStageEntity
     expose :artifacts, using: PipelineArtifactEntity
     expose :manual_actions, using: PipelineActionEntity
   end

app/serializers/pipeline_stage_entity.rb

 class PipelineStageEntity < Grape::Entity
   include RequestAwareEntity
 
-  expose :name do |stage|
-    stage.name
-  end
-
-  expose :status do |stage|
-    stage.status || 'not found'
-  end
+  expose :name
+  expose :detailed_status, as: :status, using: StatusEntity
 
-  expose :url do |stage|
+  expose :path do |stage|
     namespace_project_pipeline_path(
       stage.pipeline.project.namespace,
       stage.pipeline.project,