NPUW: Introduce basic ORC constructs (#35662)
### Details:
- ORC is a new versioned format for the NPUW internals
- This PR only brings the basic constructs (yet unstable in terms of
API), there's no integration witht he existing serialization
### Tickets:
- EISW-214505
### AI Assistance:
- *AI assistance used: yes*
- *Implemented according to spec*
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Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
