SSBC: Clean up workspace items

Created by: courier-new

Before starting, consider if it's worth pursuing this separately from #30469 (closed).

• Whole item should be clickable
• Items should match striping of Workspaces Preview from editor page
• Icon should occupy its own column
• Text styles should match Workspaces Preview
• Header should be h4 and match Workspaces Preview

See Rob's QA feedback.