[PT FE] Support prim::fork and aten::wait (openvinotoolkit#26839)

### Details:
 - *Support `prim::fork` and `aten::wait`*

### Tickets:
 - *CVS-153613*

---------

Co-authored-by: Michal Lukaszewski <michal.lukaszewski@intel.com>

src/bindings/python/src/openvino/frontend/pytorch/ts_decoder.py

@@ -73,7 +73,6 @@ def __init__(
                     "https://pytorch.org/tutorials/beginner/Intro_to_TorchScript_tutorial.html."
                 ) from e
             self.graph_element = pt_module.inlined_graph
-            log.debug("Inlined graph:\n%s", pt_module.inlined_graph)
             self.alias_db = self.graph_element.alias_db()
         else:
             self.graph_element = graph_element
@@ -96,6 +95,7 @@ def __init__(
             self._transform_tensor_list_constants_to_listconstruct(
                 self.graph_element)
             self._transform_optional_constants(self.graph_element)
+            log.debug("Inlined graph:\n%s", self.graph_element)
 
     @staticmethod
     def _get_preserved_attributes(model) -> list:
@@ -293,22 +293,31 @@ def decoder_type_name(self) -> str:
         return "ts"
 
     def get_subgraphs(self) -> list:
-        if self.graph_element.kind() == "prim::PythonOp":
+        if self.graph_element.kind() in ["prim::PythonOp", "prim::fork"]:
             if "Subgraph" in self.graph_element.attributeNames():
                 assert isinstance(
                     self.graph_element, torch.Node), "Graph element must be of type torch.Node."
-                return [getattr(self.graph_element, self.graph_element.kindOf("Subgraph"))("Subgraph")]
+                subgraph = getattr(self.graph_element, self.graph_element.kindOf("Subgraph"))("Subgraph")
+                torch._C._jit_pass_inline(subgraph)
+                return [subgraph]
             else:
                 # Attribute "Subgraph" is only available if Graph was created using tracing.
                 # TODO Find way to extract subgraph for scripted Graph.
                 return []
         return list(self.graph_element.blocks())
 
     def get_subgraph_decoder(self, index: int):
-        decoder = TorchScriptPythonDecoder(
-            self.pt_module, self.get_subgraphs(
-            )[index], alias_db=self.alias_db, shared_memory=self._shared_memory, module_extensions=self.module_extensions
-        )
+        module = self.pt_module
+        if self.graph_element.kind() == "prim::fork":
+            in0 = self.raw_inputs[0]
+            if in0.node().kind() == "prim::GetAttr":
+                module, _ = get_value_from_getattr(in0.node(), self.pt_module)
+        decoder = TorchScriptPythonDecoder(module,
+                                           self.get_subgraphs()[index],
+                                           alias_db=self.alias_db,
+                                           shared_memory=self._shared_memory,
+                                           module_extensions=self.module_extensions
+                                           )
         self.m_decoders.append(decoder)
         return decoder
 
@@ -456,8 +465,8 @@ def as_string(self):
 
     @staticmethod
     def _as_constant_list(pt_value: torch.Value):
-        # For now it is treat a list as a 1D tensor; it is required by converters to avoid need to massively
-        # rewrite them in that part where constant attributes are queried
+        # For now we treat a list as a 1D tensor; it is required by converters to avoid
+        # need to massively rewrite them in that part where constant attributes are queried
         pt_element_type = str(pt_value.type().getElementType())
         ivalue = pt_value.toIValue()
         is_known_type = pt_element_type in pt_to_ov_type_map
@@ -467,6 +476,7 @@ def _as_constant_list(pt_value: torch.Value):
             ovshape = PartialShape([len(ivalue)])
             ov_const = op.Constant(ovtype, ovshape.get_shape(), ivalue)
             return ov_const.outputs()
+        return []
 
     def _get_device_string(self) -> str:
         assert self.graph_element.kind(

src/frontends/pytorch/src/op_table.cpp

@@ -675,6 +675,7 @@ const std::unordered_map<std::string, CreatorFunction> get_supported_ops_ts() {
         {"aten::var_mean", op::translate_var_mean},
         {"aten::view", op::quantizable_op<op::translate_reshape>},
         {"aten::view_as", op::translate_reshape_as},
+        {"aten::wait", op::skip_node},
         {"aten::where", op::translate_where},
         {"aten::zero", op::translate_zeros_like},
         {"aten::zeros", op::translate_zeros},
@@ -685,6 +686,7 @@ const std::unordered_map<std::string, CreatorFunction> get_supported_ops_ts() {
         {"prim::Constant", op::translate_constant},
         {"prim::device", op::translate_constant},
         // prim::DictConstruct - Supported in limited set of patterns
+        {"prim::fork", op::translate_pythonop},
         {"prim::GetAttr", op::translate_get_attr},
         {"prim::If", op::translate_if},
         {"prim::is_cuda", op::return_false_scalar},

tests/layer_tests/pytorch_tests/test_fork_wait.py

@@ -0,0 +1,38 @@
+# Copyright (C) 2018-2024 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+import numpy as np
+import pytest
+import torch
+
+from pytorch_layer_test_class import PytorchLayerTest
+
+
+class TestForkWait(PytorchLayerTest):
+
+    def _prepare_input(self):
+        return (np.random.randn(10, 20),)
+
+    def create_model(self):
+
+        class AddMod(torch.nn.Module):
+            def forward(self, a: torch.Tensor, b: int):
+                return a + b, a - b
+
+        class Mod(torch.nn.Module):
+            def __init__(self):
+                super().__init__()
+                self.mod = AddMod()
+
+            def forward(self, input):
+                fut = torch.jit.fork(self.mod, a=input, b=2)
+                return torch.jit.wait(fut)
+
+        return Mod(), None, ["prim::fork", "aten::wait"]
+
+    @pytest.mark.nightly
+    @pytest.mark.precommit
+    @pytest.mark.parametrize(("to_trace"), [True, False])
+    def test_fork_wait(self, to_trace, ie_device, precision, ir_version):
+        self._test(*self.create_model(), ie_device, precision,
+                   ir_version, trace_model=to_trace)