Big improvements on sidepane auto/manual sizing

See gui-tests.md for the expected sidepane behaviors.

src/qml/Base/HPage.qml

@@ -27,11 +27,9 @@ SwipeView {
     interactive: sidePane.reduce
 
     SidePane {
-        canAutoSize: false
-        autoWidthRatio: 1.0
+        implicitWidth: swipeView.width
         collapse: false
         reduce: false
-        currentSpacing: theme.spacing
         visible: swipeView.interactive
         onVisibleChanged: if (currentIndex != 1) swipeView.setCurrentIndex(1)
     }

src/qml/Base/HSplitView.qml

@@ -12,8 +12,8 @@ Controls1.SplitView {
     property bool anyPressed: false
     property bool anyResizing: false
 
-    property bool canAutoSize: true
-    onAnyPressedChanged: canAutoSize = false
+    property bool manuallyResized: false
+    onAnyResizingChanged: manuallyResized = true
 
     handleDelegate: Item {
         readonly property bool hovered: styleData.hovered