* WIP: start writing combined indexing get

* list/tuple/Variable

* getitem 80%

* add setitem

* add some unittest for setitem

* lazy import

* fix some setitem error

* fix advance indexing with decreasing axes; fix strided_slice input name

* combine int-tensor getitem is ok (without boolean support & broadcast); add getitem unittest for static

* add broadcast & parse bool tensor for __getitem

* [change getitem] _getitem_impl_ to _getitem_static, not deleting the former one

* refine new getitem; fix ut in variable/var_base

* add __getitem__ ut in dygraph

* re-dispatch getitem for Py/CPP; fix strided_slice decrease axes error in dygraph

* fix ut; support tensor in slice

* [change setitem] _setitem_impl_ to _setitem_static, not deleting the former one

* remove some UT (for some, temporarily)

* add IndexError to solve timeout problem in static-mode

* 1.temply forbideen all-False bool-indexput; 2.setitem_static will return new variable

* xpu uses old stratege

* rename dy2st setitem ut to avoid same-name problem

* dy2st for new combined index

* ut case for combine-index with dy2st

* open ut with all-false-bool setitem

* remove useless doc and _getitem_impl_

* change static res

* fix static xpu

* add paddle.static.setitem

* add some help doc

* support setitem

* support machanism

* add more unittest

* remove usless code

* raise error in static setitem

* fix d2s UT

* remove static only for both-used code

* fix bool set_value in static, fix set_value_op UT

* fix unittests

* [May case some error]: remove inplace-version check

* add two test case for dy2st

* fix function in vision

* fix dy2st setitem support, refine UT case

* fix slice in static_mode

* add ParametersMap

* remove pop

* modify place

* [fix]: variable is also a tensor

* rewrite some ut & remove slicetransformer in dy2st

* solve error in static-mode

* fix ut

* return a result for set_array_write

* fix test_set_value_op_xpu

* code is different in dynamic / static mode

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Co-authored-by: NAurelius84 <zhangliujie@baidu.com>
Co-authored-by: NNotHaozi <zhangmenghao@baidu.com>