[Fluid Clean] remove nn.topk, nn.ctc_greedy_decoder, nn.im2sequence, nn.multiplex, nn.smooth_l1 (#48289)

* move softmax to paddle2.0

* fix some bugs

* resolve conflict

* remove some code

* modify code style

* fix bugs

* fix code

* fix move code

* fix some bugs

* fix code

* fix some code

* modify the header file

* fix bugs

* fix some examples

* fix mish example

* fix code

[fluid remove]: remove paddle.fluid.layers.nn.temporal_shift and paddle.fluid.layers.sigmoid_focal_loss (#48553)

* remove paddle.fluid.layers.nn.temporal_shift

* code check

* rm unittest

* remove paddle.fluid.layers.sigmoid_focal_loss

* replace pad with paddle.nn.functional.pad and fix call arguments

* solve the ImportError in PR-CI-Mac-Python3, which is called "cannot
import name 'assign' from 'paddle.fluid.layers'"

* fix the CI error of remove_pad by remove import paddle.nn.functional as
F

* fix the ImportError of remove_pad

* fix functional call of pad

* replace log with paddle.log

* replace log with paddle.nn.functional.log

* fix the code style of remove_log

* fix the ImportError of log

* fix the error of modification of the dist_transformer.py

* fix error of Static-Check

* remove pool3d

* Remove API: lod_append
	remove lod_append which is not used in Paddle 2.0

* remove lod_append test file

* move instance_norm from fluid to static

* move group_norm, data_norm to static

[Clean fluid] Clean maxout, space_to_depth, affine_channel, similarity_focus and add_position_encoding (#48410)

* Clean fluid maxout

* Clean fluid space_to_depth

* Clean fluid affine_channel and related tests

* Clean fluid similarity_focus and related tests

* Clean fluid add_position_encoding and related tests

* Fix code style

* Replace paddle.fluid.layers.gather_nd with paddle.gather_nd

* replace gather_nd with paddle.gather_nd

* fix the call of gather_nd

* fix code style of gather_nd

* Clean fluid resize_linear API

* Clean fluid image_resize_short API

* add image_resize back

* Clean psroi_pool and prroo_pool

* Clean roi_pool and roi_align

* delete test_trt_roi_align_op.py

* Remove API: squeeze
	Modify the funcation all of squeeze.
	Use paddle.squeeze to replace paddle.fluid.layers.squeeze

* Remove: squeeze
	fix some modifications which are not needless to the original
format

* Fix the function call of 'squeeze' from old style to new style.

* modify the call of squeeze from old style to new style

* Modify the call of squeeze from old style to new style

* replace squeeze with paddle.squeeze

* modify the nn.py based on the review suggestion

remove a redundant comment.

* remove one comment which is not necessary

* remove crop_tensor which is not used in paddle 2.0

* replace the crop_tensor with paddle.crop in orgnizing network

* remove flatten in nn.py under fluid

* fix test case

* fix test case

* fix codestyle

* fix codestyle

* fix code style

* remove extra test case

* remove test case

* remove fluid.reduce_sum

* remove fluid.reduce_sum

* modify axis and import paddle

* modify keepdim and out_name

* modift unittest

* modift unittest

* modify CI_static and loss.py

* modify test_mse_loss

* modify static ci

* modify static ci datatype

* add import paddle in test

* fix conflict

* fix conflict

* modify ci

* modify ci

* fix_conflict

* fix bug

* code_style

remove random_crop which is not used in Paddle 2.0

* Clean fluid resize_linear API

* Clean fluid image_resize_short API

* add image_resize back

* move conv3d

* remove unused import

* remove brelu in nn.py under fluid

* add brelu op test case