[WIP] Add eye op

[Zailiang]

1. 用 ones 和 diag 拼成的 eye op：ones生成全1矩阵，再用diag保留对角线值，其他全为0，从而实现eye。
2. 测试脚本暂未跑通，待diag op的PR PR4080 完成合并后，再完善此PR。

[CLAassistant]

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8 out of 11 committers have signed the CLA.

:white_check_mark: hengzi
:white_check_mark: MARD1NO
:white_check_mark: leaves-zwx
:white_check_mark: hjchen2
:white_check_mark: simonJJJ
:white_check_mark: Ldpe2G
:white_check_mark: BBuf
:white_check_mark: Zailiang
:x: iamyf
:x: Ziheng-ZHAO
:x: WangTuoxyty
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