V1/feature/menu items hide actions

[JesmoDev]

Sets the width of the uui-menu-item action slot to 0 when not hovered or focused (previously just opacity) This gives the text in the menu item more space, which is useful in narrow layouts.

Example of problem: There's a lot of wasted space on the right side of the menu-item

Example form Storybook Before:

After:

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Chore (minor updates related to the tooling or maintenance of the repository, does not impact compiled assets)

Checklist

• [x] If my change requires a change to the documentation, I have updated the documentation in this pull request.
• [x] I have read the CONTRIBUTING document.
• [x] I have added tests to cover my changes.