Iterate on approvals rules table layout
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## Columns width
Following the discussion from #432719, we want to limit the width of the action column:
> Since the `Actions` is limited to edit and delete as the max number of actions, could we fix the width of Actions column? This way we could align consistently with either a left or center alignment? I would optimize for whatever looks best here with this column.
https://gitlab.com/gitlab-org/gitlab/-/issues/432719#note_1746986468
To do that, we need to change `table-layout` CSS property to `fixed` and rework the columns width in order to keep the current layout. Currently, not all columns have a defined width.
## Collapsible table
The tables have been quite recently changed to a collapsible layout. Using `b-table-stacked-md` from Bootstrap Vue, the header is not displayed below `md` breakpoint and the table use `:data-label` attributes to display each item's header. But we still have leftover styling. Even though the whole `<thead>` get's `display: none`, elements within it have the following classes:
- `d-none d-sm-table-row`
- `d-none d-sm-table-cell`
Make sure that `ee/app/assets/javascripts/approvals/project_settings/project_rules.vue` is free of classes that are redundant. If any of those are still necessary exchange them into GitLab UI utility classes (`gl-display-none` etc.).
issue