[Panel Edit Mode] Show screen edge button and panel size button tooltips immediately after click

Summary: This sets the delay of the tooltips added in D17323 to 0, so they are immediately shown when you click on the buttons.

Test Plan: Click on the two buttons in the Panel Edit Mode.

Reviewers: #plasma, #vdg, ngraham

Reviewed By: #vdg, ngraham

Subscribers: #vdg, plasma-devel, #plasma

Tags: #plasma, #vdg

Differential Revision: https://phabricator.kde.org/D17622