Fix column autosize

[severo]

When double clicking a column, it autotunes the column width. But it's slightly off, at least on https://huggingface.co/spaces/hyperparam/hyperparam?url=https%3A%2F%2Fhuggingface.co%2Fdatasets%2Fnvidia%2FOpenCodeReasoning%2Fblob%2Fmain%2Fsplit_1%2Ftrain-00006-of-00010.parquet

[severo]

Also in the demo: https://hyparam.github.io/demos/hyparquet/?key=https%3A%2F%2Fhuggingface.co%2Fdatasets%2Fnvidia%2FOpenCodeReasoning%2Fresolve%2Fmain%2Fsplit_1%2Ftrain-00006-of-00010.parquet

[severo]

Note that it affects resize by double clicking the separator, but more importantly: the initial widths

See #118 (comment)

[severo]

Current rendering in storybook for the initial width:

[severo]

fixed by #125