* add pool2d3d API,test=develop

* add api unitest,test=develop

* fix unittest, test=develop

* fix reviews, test=develop

* return one element when return indices is true, test=develop

* fix low converage; to_variable to to_tensor, test=develop

* sort API params, test=develop

* fix en doc, merge PR#26108 to here, test=develop

* fix en doc, test=develop

* add adaptive_avg_pool2d

* add adaptive_avg_pool3d