allow to set custom icon for the left drawer handle
Summary:
it allows to set a icon to the globaldrawer handle, for that both close and open handle icons need to be set
FEATURE: 405598
FIXED-IN: 5.62
Reviewers: Kirigami, mart
Reviewed By: Kirigami, mart
Subscribers: ngraham, plasma-devel
Tags: Kirigami
Differential Revision: https://phabricator.kde.org/D23154