Create action button helper component

It may be helpful to create a component that automatically formats action icon buttons in a way that conforms with usage guidance.

Something very vaguely like:

• accepts an actions prop that's an array of objects, each of which defines props to pass to the related action button
• When there are fewer than some cutoff number (3? 4?), they are rendered as separate icon buttons
• When there are more than the cutoff number, they are rendered as a dropdown

see discussion at gitlab!182136 (comment 2376097224)

Benefits

• Less repetitive code in FE
• Consistency of layout and behavior

Drawbacks

• Wouldn't apply for haml-based views
• requires refactoring to put in place
• A change to the desired behavior in future requires a new version of gitlab-ui