Plugins: show plugin icons in bulk edit mode

[rickybanister]

In the latest design it feels better to keep the plugin icon visible when you enter bulk edit mode. The select checkbox only takes up 40 or so horizontal pixels. The plugin icons do a great deal to make the list more scannable. It also makes it much easier to vertically-center the checkbox (no need to rely on the line-height of the plugin title).

We should transition to a more flex-based layout of the plugins list while doing this, it'll make things easier to align.

Currently:

Ideally: