Expand clickable area in blueprints list

[martenbjork]

It seems that the area indicated in red can't be clicked. However, it has a hover effect which indicated that it's clickable.

I found this confusing when I was quickly clicking through the items — sometimes my click wouldn't register.

[abey79]

I suspect that the area covered by the 2px expansion is not actually clickable. This control will need a complete rewrite I believe:

• it needs the proper triangle (Use design system arrow icon across the app #2738)
• it needs suppression of the expansion effect on the triangle
• it needs better control the highlight area (which is negatively affected by suppressing the expansion, and is hard to work around)

[abey79]

Fixed by #3118