Fix compact attribution style when using global CSS that sets box-sizing: border-box;

[simondriesen]

Fixes #10585

Summary

• For front-end developers it's common practice to globally set the CSS box-sizing property to border-box for all elements. Like w3schools.com writes: "Applying this to all elements is safe and wise".
• The CSS of the attribute control is written assuming box-sizing is set to content-box, causing developers that have globally set box-sizing: border-box to have the visual bug as seen in the GIF above.
• My solution would be specifying the CSS property box-sizing value for .mapboxgl-ctrl-attrib so global user preferences don't influence the styling of the compact attribution control.
• This approach was already taken for .mapboxgl-ctrl-scale so I would say it's a consistent solution.

Steps to Trigger Behavior

1. Setup a map with an compact attribution control.
2. Define the following CSS anywhere in your application:

* {
  box-sizing: border-box;
}

Launch Checklist

• Make sure the PR title is descriptive and preferably reflects the change from the user's perspective.
• Add additional detail and context in the PR description (with screenshots/videos if there are visual changes).

[CLAassistant]

All committers have signed the CLA.

[stepankuzmin]

Good catch, thanks @simondriesen!