OPCUA emulator (Lewis or otherwise)

# Feature Description

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As a developer, I would like to have an OPCUA server emulator which allows me to test any OPCUA IOC within the current unit testing framework.
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## Explanation
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[comment]: <> (FILL IN BELOW)
>asyncua branches off of asyncio, and therefore it's required to wait for the Lewis refactor work before integrating an OPCUA server emulator into Lewis. This ticket is to make a smaller, command line emulator, similar to the Mezei Flipper emulator in Device Emulator.

### Additional Information

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# Acceptance Criteria
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# How to Review
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