Fix HButton height for icon-only buttons

The button only considered its label previously to calculate its
implicit height.

src/gui/Base/HButton.qml

@@ -8,8 +8,7 @@ Button {
     id: button
     enabled: ! button.loading
     spacing: theme.spacing
-    topPadding:
-        padded ? spacing * (circle ? (iconItem.small ? 1.5 : 1.8) : 0.5) : 0
+    topPadding: padded ? spacing * (circle ? 1 : 0.5) : 0
     bottomPadding: topPadding
     leftPadding: padded ? spacing : 0
     rightPadding: leftPadding

src/gui/Base/HButtonContent.qml

@@ -26,6 +26,8 @@ HRowLayout {
 
         Layout.preferredWidth:
             button.loading ? busyIndicatorLoader.width : icon.width
+        Layout.preferredHeight:
+            button.loading ? busyIndicatorLoader.height : icon.height
 
         Layout.fillHeight: true
         Layout.alignment: Qt.AlignCenter