Adding spacing between navigation group components, fixing height for…

[joelclimbsthings]

Fixes #26336

The design for the navigation component has been updated to require a few minor CSS updates; including:

• The individual items should have a height of 32px
• Consecutive groups should have a 24px spacing
• Cancelling native margin styles present in wp-admin environment

Description

Only some minor CSS additions in navigation-styles.scss that only impact the experimental navigation component.

How has this been tested?

• Viewing the usage of the navigation component within the wc-admin environment
• Viewing the component within Storybook
• Running linting/tests

Screenshots

Before:

After:

Types of changes

Bug fix, updating to align with newer designs for experimental navigation components

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.