[applets/notes] Fix drag&drop links and cursor shape regression

Summary:
Restore the possibility to drag and drop the links from browser, and the cursor shape now changes on links.

BUG: 417953
FIXED-IN: 5.18.3

Reviewers: #plasma, ngraham

Reviewed By: ngraham

Subscribers: ngraham

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D27673