Set default options for the dev command, similar to the preview command.

This shouldn't break anything, but could be helpful:

1. Ensure port is 3000, as Vite 3 changes to 5173.
2. Set --host to localhost as Vite defaults to 127.0.0.1 in dev.

Re no2, while Vite still forces 127.0.0.1 when localhost is specified (ref vitejs/vite#7075), this will be changed in Vite 3 and the behaviour should be consistent with preview then.

Also ref: #4729

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