Render labels using Text.QtRendering on OSX

Fonts were looking a bit to thick on when using `Text.NativeRendering`, so using `Text.QtRendering` instead. After this the font weight looks identical to figma (as far as I can see).

In this commit I also changed all `Label`'s to `UM.Label`'s and removed default properties where I could.

CURA-9154

plugins/Marketplace/resources/qml/PackageCardHeader.qml

@@ -87,11 +87,10 @@ Item
             Layout.preferredWidth: parent.width
             Layout.preferredHeight: childrenRect.height
 
-            Label
+            UM.Label
             {
                 text: packageData.displayName
                 font: UM.Theme.getFont("medium_bold")
-                color: UM.Theme.getColor("text")
                 verticalAlignment: Text.AlignTop
             }
             VerifiedIcon
@@ -100,12 +99,10 @@ Item
                 visible: packageData.isCheckedByUltimaker
             }
 
-            Label
+            UM.Label
             {
                 id: packageVersionLabel
                 text: packageData.packageVersion
-                font: UM.Theme.getFont("default")
-                color: UM.Theme.getColor("text")
                 Layout.fillWidth: true
             }
 
@@ -155,14 +152,11 @@ Item
             spacing: UM.Theme.getSize("narrow_margin").width
 
             // label "By"
-            Label
+            UM.Label
             {
                 id: authorBy
                 Layout.alignment: Qt.AlignCenter
-
                 text: catalog.i18nc("@label", "By")
-                font: UM.Theme.getFont("default")
-                color: UM.Theme.getColor("text")
             }
 
             // clickable author name