Add LangChain.js adapter for OpenVINO

[Retribution98]

Details:

• This PR implements a LangChain.js adapter for OpenVINO.
• The OpenVINO LangChain.js adapter uses openvino-node, openvino-genai-node and openvino-tokenizers-node packages from NPM.
• The OpenVINO LangChain.js adapter should not be built as an external module with OpenVINO. Therefore, it is placed in a new folder called adapters.
• The OpenVINO LangChain.js adapter will be published on NPM.

[almilosz]

Looks good to me! Changes were tested using latest openvino-node and openvino-genai packages from master branches.
Let's merge after packages for 2025.2.0 will be released.

[alvoron]

LICENSE file is not required - all repository modules are licensed under Apache, the license file is in repo root.
All 3rd party dependencies need to be listed in third-party-programs.txt