Use runWithPlugin helper in SharePlugin
Summary: Depends on D16472
Test Plan:
Share file via app
Share file from external app
Share file via direct Share
Reviewers: KDE Connect, albertvaka
Reviewed By: KDE Connect, albertvaka
Subscribers: albertvaka, kdeconnect
Tags: KDE Connect
Differential Revision: https://phabricator.kde.org/D16473