Highlight queued transaction pending a signature

[katspaugh]

Based on user feedback from Karpatkey.

It's hard to see in the queue which transactions you must sign. Their suggestion was to highlight them somehow. Or maybe even push them to the top.

Also, on the Dashboard, in the pending txs widget, we show top 5 queued transaction regardless of whether the connected wallet has already signed them. It should show only signable txs.

cc @liliiaorlenko