Summary:
Show an icon for each notification which has an icon.

	Show a toolbutton which can be used to reply to notifications which offer a quick reply.

Reviewers: #kde_connect, albertvaka

Reviewed By: #kde_connect, albertvaka

Subscribers: albertvaka

Maniphest Tasks: T4674, T4658

Differential Revision: https://phabricator.kde.org/D6058