Show banner in case of unsigned lists

[goomens]

Component

Main grade submission screen

Summary

Add a banner on top of the screen if there are any lists that have been submitted but still need to be signed.

Reported by

FGw (Joris) in AC2106 10991

[ftbloem1]

To emphasize the call to action with users, they seem to easily miss the current notification.

[goomens]

[goomens]

Clarify clickability of links. List icon, blue + underline?