Set position and width of card in details page

This means that the card itself shouldn't specify a width. It should get a width from how it's used.

Contributes to issue CURA-8565.

plugins/Marketplace/resources/qml/PackageCard.qml

@@ -12,7 +12,6 @@ Rectangle
 {
     property var packageData
 
-    width: parent ? parent.width - UM.Theme.getSize("default_margin").width - UM.Theme.getSize("narrow_margin").width: 0
     height: UM.Theme.getSize("card").height
     color: UM.Theme.getColor("main_background")
     radius: UM.Theme.getSize("default_radius").width

plugins/Marketplace/resources/qml/PackageDetails.qml

@@ -70,6 +70,15 @@ Item
         PackageCard
         {
             packageData: detailPage.packageData
+            anchors
+            {
+                left: parent.left
+                leftMargin: UM.Theme.getSize("default_margin").width
+                right: parent.right
+                rightMargin: anchors.leftMargin
+                top: parent.top
+                topMargin: UM.Theme.getSize("default_margin").height
+            }
         }
     }
 }

plugins/Marketplace/resources/qml/Packages.qml

@@ -77,6 +77,7 @@ ListView
         PackageCard
         {
             packageData: model.package
+            width: parent.width - UM.Theme.getSize("default_margin").width - UM.Theme.getSize("narrow_margin").width
         }
     }