cnap: fix the inference info in pipeline table and fix cleanup

[Hulongyin]

This PR is to fix wrong infer fps display on SPA and wrong inference info in pipeline table when scale up/down the replicas of inference service.

• modify infer_engine_info to infer_engine_dict in pipeline table
• add inference engine to pipeline table when set fps for the first time
• cleanup after wait_all_tasks_end in MicroAppBase
• add clean_infer_engine in the cleanup of inference service