Adding a way to create multiple cursors that can insert/remove text at
arbitrary positions in the document. Adding cursors is done by pressing
alt + up/down or by clicking into the editor while holding the alt key.
Fixes: QTCREATORBUG-16013
Change-Id: I495d27d95a3d277220946616ef30efc241da0120
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Artem Sokolovskii <artem.sokolovskii@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>
