Rewrite workspace KCM in QtQuick

Summary:
This patch renews the System Settings -> Desktop Behaviour -> Workspace.

Basically it is rewritten in QML, ConfigModule. Also, its naming has been
changed. It was called as kcm_workspaceoptions and workspaceoptions before
but now, it is kcm_workspace like other renewed KCMs' names.

Currently, ToolTip and VisualFeedback working fine. All the functionalities
are tested. "Default", "Reset" buttons works like a charm.

{F5852481}

Reviewers: romangg, ngraham, #plasma

Reviewed By: romangg, #plasma

Subscribers: zzag, davidedmundson, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D12936