Make the incidence info popup background nicer to look at

With changes:

![Screenshot_20220914_180915](/uploads/c072957f2fb8c4e954a8246eda983186/Screenshot_20220914_180915.png)

Before:

![image](/uploads/5abb5566c610500feb5c02ea77bf1199/image.png)

Signed-off-by: Claudio Cambra <claudio.cambra@gmail.com>

src/contents/ui/Controls/IncidenceInfoPopup.qml

@@ -14,21 +14,34 @@ QQC2.Popup {
     id: root
 
     property var incidenceData
-
     property alias scrollView: incidenceInfoContents.scrollView
 
     contentWidth: availableWidth
 
-    topPadding: 0
-    leftPadding: 0
-    rightPadding: 0
-    bottomPadding: 0
+    clip: false
+
+    background: Kirigami.ShadowedRectangle {
+        Kirigami.Theme.inherit: false
+        Kirigami.Theme.colorSet: Kirigami.Theme.View
+
+        color: Kirigami.Theme.backgroundColor
+        radius: Kirigami.Units.largeSpacing
 
-    Kirigami.Theme.colorSet: Kirigami.Theme.Window
+        shadow.size: Kirigami.Units.largeSpacing
+        shadow.color: Qt.rgba(0.0, 0.0, 0.0, 0.2)
+        shadow.yOffset: 2
+
+        border.width: 1
+        border.color: Kirigami.ColorUtils.tintWithAlpha(color, Kirigami.Theme.textColor, 0.2)
+    }
 
     contentItem: IncidenceInfoContents {
         id: incidenceInfoContents
         anchors.fill: parent
+        anchors.left: Kirigami.Units.largeSpacing
+        anchors.right: Kirigami.Units.largeSpacing
+
+        clip: true
         incidenceData: root.incidenceData
     }
 }