feat(StatusListItem): support letter identicons

This adds support for letter identicons by using the `icon.isLetterIdenticon`
flag:

```qml
StatusListItem {
    title: "Some name"
    icon.isLetterIdenticon: true
    icon.background.color: "orange"
}
```

Closes #239

sandbox/ListItems.qml

@@ -230,6 +230,12 @@ GridLayout {
         type: StatusListItem.Type.Secondary
     }
 
+    StatusListItem {
+        title: "Title"
+        icon.isLetterIdenticon: true
+        icon.background.color: "orange"
+    }
+
     StatusDescriptionListItem {
         title: "Title"
         subTitle: "Subtitle"

src/StatusQ/Components/StatusListItem.qml

@@ -34,6 +34,7 @@ Rectangle {
         height: 20
         width: 20
         rotation: 0
+        isLetterIdenticon: false
         background: StatusIconBackgroundSettings {
             width: 40
             height: 40
@@ -78,8 +79,15 @@ Rectangle {
             anchors.left: parent.left
             anchors.leftMargin: statusListItem.leftPadding
             anchors.verticalCenter: parent.verticalCenter
-            sourceComponent: !!statusListItem.icon.name ? statusRoundedIcon : statusRoundedImage
-            active: !!statusListItem.icon.name || !!statusListItem.image.source.toString()
+            sourceComponent: {
+                if (statusListItem.icon.isLetterIdenticon) {
+                    return statusLetterIdenticon
+                }
+                return !!statusListItem.icon.name ? statusRoundedIcon : statusRoundedImage
+            }
+            active: statusListItem.icon.isLetterIdenticon || 
+                    !!statusListItem.icon.name || 
+                    !!statusListItem.image.source.toString()
         }
 
         Component {
@@ -104,6 +112,16 @@ Rectangle {
             }
         }
 
+        Component {
+            id: statusLetterIdenticon
+            StatusLetterIdenticon {
+                width: statusListItem.icon.background.width
+                height: statusListItem.icon.background.height
+                color: statusListItem.icon.background.color
+                name: statusListItem.title
+            }
+        }
+
         Item {
             anchors.left: iconOrImage.active ? iconOrImage.right : parent.left
             anchors.leftMargin: statusListItem.leftPadding

src/StatusQ/Core/StatusIconSettings.qml

@@ -10,5 +10,6 @@ QtObject {
     property color color
     property url source
     property int rotation
+    property bool isLetterIdenticon
     property StatusIconBackgroundSettings background: StatusIconBackgroundSettings {}
 }