Add edit-line-width icons

Summary:
Add edit-line-width icons required for T8076.

CCBUG:408283

Test Plan: {F7521595}

Reviewers: #vdg, ndavis

Reviewed By: #vdg, ndavis

Subscribers: ngraham, ndavis, kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D24412