Added openvino torch backend import statement in init files (#19208)

* Added openvino torch backend import statement in init files

* Added openvino/torch folder for simplyfing the import

* Removed imports from all the other init.py files

* Fixed flake8 issues

* Removed requirements.txt

* Removed redundant functions

src/bindings/python/src/openvino/frontend/pytorch/torchdynamo/backend.py

@@ -36,7 +36,7 @@ log = logging.getLogger(__name__)
     We can then use this model for inference. We only need to add two lines of code to
     the Pytorch applications which are marked in the code below
 
-    1) import openvino.frontend.pytorch.torchdynamo.backend
+    1) import openvino.torch
     model = torchvision.models.resnet50()
     2) model = torch.compile(model, backend="openvino")
 """

src/bindings/python/src/openvino/torch/__init__.py

@@ -0,0 +1,5 @@
+# -*- coding: utf-8 -*-
+# Copyright (C) 2018-2023 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+from openvino.frontend.pytorch.torchdynamo import backend