Draft: Allow update track rating from ContextView and PlayListEntry

Changes to ContextView (Now Playing) and PlayListEntry to allow update track rating directly.

(https://bugs.kde.org/show_bug.cgi?id=437099)

When the playlistentry is hovered, durationLabel is hidden to optimize space,

LabelWithToolTip {
    id: durationLabel

    ...
    visible: !containsMouse && !isSelected && !playListEntry.activeFocus && !simpleMode
}

otherwise the result would be this, (what do you think?) ...