[rbren no-retries] add user-friendly messages

[enyst]

This PR proposes to add user-friendly messages in natural language, for the exceptions we no longer retry on.

Also fixes docs for the new behavior.

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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:8c43803-nikolaik   --name openhands-app-8c43803   docker.all-hands.dev/all-hands-ai/openhands:8c43803