Wallpaper refining (#81)

* Wallpaper refining

- Swww: allow all images formats supported by Swww but only show the one
we can render in the panel
- Fix: timer should be restarted when selecting a wallpaper
- Fix: avoid recomputing selected thumbnail by altering the border width
- Removed LazyLoader as it was not helping

* Wallpapers changes

- revert: maintaining a single list all wallpapers, support only basic
images format.
- settings: reordered wallpapers settings and made the Swww settings
conditionals to activating the useSWWW toggle

* Fix broken avatar display in Panel, Settings and LockScreen

---------

Co-authored-by: Sébastien Atoch <sebastien@atracktiv.com>

Widgets/LockScreen/LockScreen.qml

@@ -161,14 +161,21 @@ WlSessionLock {
                 radius: 40
                 color: Theme.accentPrimary
 
+                Rectangle {
+                    anchors.fill: parent
+                    color: "transparent"
+                    radius: 40
+                    border.color: Theme.accentPrimary
+                    border.width: 3
+                    z: 2
+                }
+
                 Avatar {}
 
                 layer.enabled: true
                 layer.effect: MultiEffect {
                     shadowEnabled: true
                     shadowColor: Theme.accentPrimary
-                    // radius: 8
-                    // samples: 16
                 }
             }