docs(prompt prefix): rename picodata -> sql, lua

Summary

• docs(prompt prefix): rename picodata -> sql, lua

Address changes from picodata@91815ef8 (24.7.0-984)

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• Staging: https://docs.binary.picodata.io/picodata/asabirov_edit_cli_prompt_prefix
• Follow-up for picodata!1435 (merged)