Add WebSocket commands for script/automation/scene config editing

[altendky]

The config editors for scripts, automations, and scenes (create/update/delete in their YAML files) appear to only be accessible via REST endpoints (POST/DELETE on /api/config/{domain}/config/{key}). I haven't been able to find WebSocket equivalents -- the existing script/config and automation/config WS commands seem to be read-only.

This hasn't been a problem since the frontend (the only consumer) uses REST. But non-browser clients that communicate over WebSocket (e.g. MCP servers for AI assistants) currently have no way to create, update, or delete script/automation/scene configurations.

Would WebSocket write commands for these config editors be welcome? I'm happy to put together a PR if so.