Remove spacing from WorkItemTypeIcon

What does this MR do and why?

This MR removes spacing from WorkItemTypeIcon so consumers don't need to override it

Screenshots or screen recordings

No visual changes

Before	After

How to set up and validate locally

Check the work item type icons on the following pages:

• Issues list http://127.0.0.1:3000/flightjs/Flight/-/issues
• Issue page http://127.0.0.1:3000/flightjs/Flight/-/issues/1
• Boards http://127.0.0.1:3000/flightjs/Flight/-/boards
• Work item detail (create task in an issue then open the task)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.