Make it obvious what "Display window borders for maximized windows" is for

Summary:
Change "Display window borders for maximized windows" to "Allow resizing maximized windows from window esges"

This makes it obvious what the purpose of the feature is, and why one would want to turn it on.

CCBUG: 387675

Test Plan:
Tested in KDE Neon. feature still works, and only the text is changed. Before:
{F5540181}

After:
{F5542554}

Reviewers: hpereiradacosta, #breeze, #vdg

Reviewed By: hpereiradacosta

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D9284