feat(frontend): Chat interface empty state

[amanape]

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

• renders repo-based suggestions
• clicking an option sends a user message event to display in UI
• selected suggestion is sent to socket after runtime is active
• chat interface now has a new micro-indicator that shows the state of the runtime (green is active and red is inactive)

RUNTIME INACTIVE

RUNTIME ACTIVE

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Resolves #4774

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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:3eeaf7e-nikolaik   --name openhands-app-3eeaf7e   docker.all-hands.dev/all-hands-ai/openhands:3eeaf7e

[xingyaoww]

👀 look forward to this

[rbren]

@amanape can we make it so that clicking a button just fills out a draft message, rather than sending it? Similar to how we had it in the old homepage