support tensor slice using constexpr

remove tensorslice metagraph

add pynative testcases

Merge pull request !1840 from wangcong/master

Merge pull request !1989 from guozhijian/fix_distribute_shuffle

Merge pull request !1966 from chujinjin/fix_loadinputdata_for_pynative

Merge pull request !1913 from xiefangqi/xfq_support_coco

Merge pull request !1998 from heleiwang/fix_api_help_wrong

Merge pull request !1965 from chenzhongming/master

Merge pull request !1918 from riemann_penn/sparse_grad_for_gatherv2

Merge pull request !1930 from jiangjinsheng/issue_doc

!1976 Lower expectation of accuracy after 1 epoch of resnet50 testcase training, decrease from 0.35 to 0.2
Merge pull request !1976 from yanghaoran/master

Merge pull request !1975 from Kang/master

Merge pull request !1954 from Xiaoda/1-fix-some-codestyle-warnings-in-parallel-module

Merge pull request !1868 from huanghui/insert-memcpy-async-pass

Merge pull request !1944 from wangqiuliang/move-hook-function-to-primitivepy

Merge pull request !1938 from Chong/ReID

Merge pull request !1982 from Tinazhang/pylint-error

Merge pull request !1908 from Tinazhang/ut-normalize

Merge pull request !1928 from yoonlee666/deletereshape

Merge pull request !1964 from meixiaowei/master

Merge pull request !1937 from chujinjin/add_async_ops_excute_for_pynative

Merge pull request !1968 from jiangjinsheng/vm_FusedMulApplyMomentumExtern

Merge pull request !1971 from zhoufeng/enable-label-task

Merge pull request !1866 from heleiwang/gnn_june

Merge pull request !1961 from jiangjinsheng/issue_net

Signed-off-by: Nzhoufeng <zhoufeng54@huawei.com>

1. support get_all_edges, get_nodes_from_edge, get_sampled_neighbors, get_neg_sampled_neighbors and graph_info API
2. mod cora and citeseer conversion script