Increase dataset edit modal size using more of the available screen space

## Screenshot

On a laptop screen:

On a larger screen:

## Description

When editing a dataset, the modal window is quite small compared to the available screen space (in green on my screenshots), which creates a lot of friction in creating new calculated columns and metrics or modifying the existing ones.

## Design input

- Maybe increase the size of the modal so that it takes around 90% of the screen space (`design:suggest`)

Thanks a lot in advance!

Start by locating the dataset edit modal in the Superset frontend and compare its current dimensions with the available viewport shown in the screenshots. Confirm the desired behavior with maintainers, then verify that the modal uses roughly 90% of the screen without making dataset editing difficult at laptop sizes.

Written by the indexing model from the issue text.