improve efficiency of runtime InferVarType (#22778)
* save InferVarType changes, test=develop
* remove code comments, test=develop
* tweak code, test=develop
* fix compilation warning, update merge_ids_op split_ids_op to new interface, test=develop
* modify fused_bn_activation_op, test=develop
* fix error of fused_bn_activation_op, test=develop
* fix PADDLE_ENFORCE and unittest coverage issue, test=develop
* tweak PADDLE_ENFORCE messages, test=develop
* improve unittest coverage, test=develop
* add StaticGraphInferVarType class, test=develop
* rebase develop branch, test=develop
* fix unittest error, test=develop
* remove comments, test=develop
* improve unittest coverage, test=develop
* imporve error message and imporve unittest coverage, test=develop
* upgrade InferVarType API, test=develop
* tweak pyfunc error message, test=develop
* fix compilation conflict - save_combine_op, test=develop