* refactor the optional tensor

* remove optiona<MetaTensor> in InferMeta

* fix bug

* fix optional<vector<Tensor>>

* fix bug

* fix rmsprop

* fix amp of eager_gen

* polish code

* fix deleted code

* fix merge conflict

* polish code

* remove is_nullopt_

* fix merge conflict

* fix merge conflict

* add eids result for graph_sample_neighbors

* fix bug

* move fisher_yates sample to warp

* add cpu eid output

* delete comment

* delete comment

* change nullptr placeholder

* optimize sample kernel

* fix mutable_data

* Add graph_reindex API

* add graph_sample_neighbors api

* Add buffer

* delete VLOG

* delete thrust::copy for output

* add ShareDataWith

* delete graph_reindex hashtable output

* add graph_reindex dispensable

* add reindex unittest, move memset to cuda kernel, change api

* fix conflict

* add reindex buffer for gpu version note

* fix conflicts for op_func_generator

* Add fisher_yates sampling, add dispensable, change infermeta

* add dtype for edge_id

* fix rocm ci and static check ci

* add unittest

* fix unittest

* fix unittest

* fix bug