improve dock settings windows geometry calculation

--the dock settings window calculations should not look
different between different font settings/geometries/screens.
One way to overcome that issue is by using the font.height to
calculate the settings height, that is 37chars for now and
the width to be calculated in accordance with that height. There
are some down limits for both, height shouldnt overcome screens
height and shouldnt go under 400px  and the width can not be
less than 200px

CCBUG: 397038

shell/package/contents/configuration/LatteDockConfiguration.qml

@@ -40,11 +40,12 @@ import "../controls" as LatteExtraControls
 FocusScope {
     id: dialog
 
-    property int maxWidth: Math.max(34 * theme.defaultFont.pixelSize, 0.85 * height)
+    property int maxWidth: Math.max(200, 0.87 * proposedHeight)
+    property int proposedHeight: Math.min(dock.screenGeometry.height - dock.normalThickness - 2*units.largeSpacing,
+                                          Math.max(400, 37 * theme.mSize(theme.defaultFont).height))
+
     width: maxWidth + units.smallSpacing * 2
-    height: Math.min(content.height + units.smallSpacing * 2,
-                     dock.screenGeometry.height - dock.normalThickness - 2*units.largeSpacing)
-    //! for small resolutions we better limit the size of the settings in order to be shown properly
+    height: proposedHeight
 
     Layout.minimumWidth: width
     Layout.minimumHeight: height
@@ -361,10 +362,7 @@ FocusScope {
             border.color: theme.backgroundColor
 
             //fix the height binding loop when showing the configuration window
-
-            property int availableFreeHeight: Math.min(29*theme.mSize(theme.defaultFont).height + units.smallSpacing * 2, //calculatios according to font size
-                                                       dock.screenGeometry.height - dock.normalThickness - 2*units.largeSpacing - header.height - headerSpacer.height
-                                                       - tabBar.height - actionButtons.height - 36) //calculations according to screen geometry and elements heights
+            property int availableFreeHeight: dialog.proposedHeight - header.height - headerSpacer.height - tabBar.height - actionButtons.height - 2 * units.smallSpacing
 
             PlasmaExtras.ScrollArea {
                 id: scrollArea