Add VSCode Hello World extension

[rbren]

End-user friendly description of the problem this fixes or functionality that this introduces

• Include this change in the Release Notes. If checked, you must provide an end-user friendly description for your change below
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Give a summary of what the PR does, explaining any non-trivial design decisions

This is a POC which adds a "hello world" vscode extension into the installed VSCode instance. It's essentially a no-op, but you can check that it's working by running cmd+shift+p and typing "OpenHands". You'll see this command

We can use the to alter the behavior of VS Code, e.g. to start on a different screen.

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Link of any specific issues this addresses

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:2332660-nikolaik   --name openhands-app-2332660   docker.all-hands.dev/all-hands-ai/openhands:2332660

[enyst]

CI is failing, it looks like the files weren't copied yet?

Happy to see this PR. IMO the vscode integration is a great direction.