qml: add rounded edge in MusicInfoExpandDelegate's cover

Signed-off-by: Pierre Lamot <pierre@videolabs.io>

modules/gui/qt/medialibrary/qml/MusicAlbumsGridExpandDelegate.qml

@@ -76,11 +76,12 @@ Widgets.NavigableFocusScope {
                 spacing: VLCStyle.margin_normal
 
                 /* A bigger cover for the album */
-                Image {
+                Widgets.RoundImage {
                     id: expand_cover_id
                     asynchronous: true
                     height: VLCStyle.expandCover_music_height
                     width: VLCStyle.expandCover_music_width
+                    radius: VLCStyle.expandCover_music_radius
                     source: model.cover || VLCStyle.noArtAlbum
                     sourceSize: Qt.size(width, height)
                 }

modules/gui/qt/style/VLCStyle.qml

@@ -166,6 +166,7 @@ Item {
 
     property int expandCover_music_height: dp(171, scale)
     property int expandCover_music_width: dp(171, scale)
+    property int expandCover_music_radius: gridCover_radius
 
     property int artistGridCover_radius: dp(90, scale)