[List] Improve border styling

[macandcheese]

Actual Behavior

There are some cases where the transparent border on the List cause the List to:

• not extend fully to the width of a container, creating a gap where background can be visible
• when filter-enabled - scrolling items will show behind the sticky input bar for 1px

Expected Behavior

The list extends to the full width of the parent container with no transparent borders. The list, when filter-enabled, does not allow the scrolled items to peek through behind the sticky input bar.

Reproduction Sample

https://codepen.io/mac_and_cheese/pen/oNMMjqJ?editors=1000

Reproduction Steps

1. Open Codepen

Reproduction Version

1.0.3

Relevant Info

No response

Regression?

No response

Impact

No response

Esri team

Calcite (design)

[mjuniper]

Here's another reproduction of the issue where it does not extend to the width of its container: https://codepen.io/mjuniper/pen/VwGOzBB?editors=1100

I think the issue is that (at least for chrome) the user agent stylesheet has a rule like:

table {
  border-spacing: 2px;
}

[github-actions]

Installed and assigned for verification.

[geospatialem]

Verified in 1.5.0-next.4.