Move extension header into separate translation unit for openvino_intel_npu_plugin library

Author: MirceaDan99

src/plugins/intel_npu/src/plugin/include/extension.hpp renamed to src/plugins/intel_npu/src/plugin/src/extension.cpp

@@ -2,9 +2,8 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-#pragma once
-
 #include "openvino/core/extension.hpp"
+
 #include "openvino/core/op_extension.hpp"
 #include "ov_ops/rms.hpp"
 

src/plugins/intel_npu/src/plugin/src/plugin.cpp

@@ -9,7 +9,6 @@
 #include "compiled_model.hpp"
 #include "compiler.hpp"
 #include "device_helpers.hpp"
-#include "extension.hpp"
 #include "intel_npu/al/config/common.hpp"
 #include "intel_npu/al/config/compiler.hpp"
 #include "intel_npu/al/config/npuw.hpp"