Add icon to browser integration do not remind menu item

Summary: {F7791325}

Test Plan: Don't have the PBI addon installed and reset its `showCount`. Then open the tray icon context menu.

Reviewers: #plasma, #vdg, davidedmundson

Reviewed By: #plasma, davidedmundson

Subscribers: #vdg, plasma-devel, #plasma

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D25635