Correctly save shortcuts of new Items
Summary:
When saving first all changes are saved before updating syscoca. This lead to a
crash because serviceByStorageId failed. We can just change the API to directly to
take KService::Ptr's.
BUG: 415699
FIXED-IN: 5.18.0
Test Plan: Correctly created a new item and set a shortcut for it
Reviewers: Plasma, rikmills, davidedmundson
Reviewed By: Plasma, davidedmundson
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D26765