feat(rust,python): reworked comfy-table layout constraints, improving table wrapping/repr

[alexander-beedie]

Ref: #9656.

The 7.x comfy-table update has turned into a good opportunity to improve our table layout/constraints. Previously the only column width/wrapping constraint that we applied came from a lower bound based on the column name/header.

This PR significantly improves constraint application by considering not only the column name, but also the dtype string/sep (if not hidden) and all of the actual (displayed|/formatted) column data. It then uses this more detailed per-column info to apply an exact bound for especially narrow columns (eg: where all elements <= 3 chars), and a combined upper/lower bound for all other columns.

During width bucket allocation for each column (by comfy-table during table creation) the presence of exact/upper bounds prevents characters from being over-allocated to columns that don't require them, reducing instances of premature/unnecessary wrapping by better-allocating the character/width budget.

With this in place we can now upgrade to the latest comfy-table, which slightly tweaked lower-bound application...

Example

Simple example showing the impact of more accurate column width determination:

import polars as pl
df = pl.DataFrame({"a": [1, 2, 3], "b": [4, 5, 6], "c": [7, 8, 9]})
with pl.Config( tbl_hide_column_data_types=True ):
    print( df )

#  before                 after    
# ┌─────┬─────┬─────┐    ┌─────┬────┬───┐
# │ aaa ┆ bb  ┆ c   │    │ aaa ┆ bb ┆ c │
# ╞═════╪═════╪═════╡    ╞═════╪════╪═══╡
# │ 1   ┆ 4   ┆ 7   │ >> │ 1   ┆ 4  ┆ 7 │
# │ 2   ┆ 5   ┆ 8   │    │ 2   ┆ 5  ┆ 8 │
# │ 3   ┆ 6   ┆ 9   │    │ 3   ┆ 6  ┆ 9 │
# └─────┴─────┴─────┘    └─────┴────┴───┘

[stinodego]

Maybe good to actually bump the comfytable version in this PR, so that we can see that it works on the latest version.

Other than that, looks fine to me!

[alexander-beedie]

Maybe good to actually bump the comfytable version in this PR, so that we can see that it works on the latest version.

Not a problem; can update it later tonight (was running with 7.0.1 locally to validate :)

[alexander-beedie]

Done; updated to the latest (7.0.1)