[wayland] Don't use hardcoded move-resize cursor
Summary:
Currently, when resizing a window the cursor doesn't match the resize
direction. The reason for that is the move-resize cursor is hardcoded.
To fix that, CursorImage::updateMoveResize has to use AbstractClient::cursor.
Also, because the move-resize cursor is updated after calling startMoveResize,
we have to connect to AbstractClient::moveResizeCursorChanged.
BUG: 370339
FIXED-IN: 5.15
Reviewers: KWin, davidedmundson, broulik, romangg, graesslin
Reviewed By: KWin, graesslin
Subscribers: davidedmundson, romangg, graesslin, kwin
Tags: KWin
Maniphest Tasks: T5714
Differential Revision: https://phabricator.kde.org/D3202