Remove NGraphFunctions namespace #27171

Job	Run time
Smart_CI	16s
Build	12m 47s
Conformance (OP)	16m 35s
Conformance (API)	2m 31s
NVIDIA plugin	9m 18s
ONNX Runtime Integration	0s
GPU_Stub	1s
OpenVINO tokenizers extension	0s
Debian Packages / Debian Packages	2m 3s
C++ unit tests / C++ unit tests	12m 54s
OpenVINO JS API / OpenVINO JS API	1m 16s
Samples / Samples	6m 8s
CPU functional tests / CPU functional tests	20m 24s
ONNX Models Tests / ONNX Models tests	25m 4s
Python unit tests	0s
TensorFlow TF Hub Models tests	0s
TensorFlow Models tests	0s
PyTorch Models tests	0s
TensorFlow Hugging Face Models tests	0s
ci/gha_overall_status	1s
	1h 49m 18s

Provide feedback