[OV JS]: Expose ov.saveModel() functionality

[hub-bla]

Details:

• Created init_function to initialize functions directly in the addon.
• Extended type_validation with Napi::Boolean
• Exposed ov.saveModel
• To make proper tests like in Python API I guess I have to wait for Model.getOps() to be exposed.

Tickets:

• Closes - https://github.com/openvinotoolkit/openvino/issues/27092