uiux: inform user early when there's no stickers installed

This makes sure we don't wait until all sticker packs are loaded
to show the user that now packs were installed (we know this much earlier).

Fixes #4127

ui/imports/shared/status/StatusStickersPopup.qml

@@ -72,6 +72,13 @@ Popup {
                 footerContent.visible = true
                 stickersContainer.visible = true
             }
+
+            Loader {
+                id: marketLoader
+                active: !root.stickerPacksLoaded
+                sourceComponent: loadingImageComponent
+                anchors.centerIn: parent
+            }
         }
 
         Item {
@@ -87,7 +94,7 @@ Popup {
             Item {
                 id: noStickerPacks
                 anchors.fill: parent
-                visible: false
+                visible: installedPacksCount == 0
 
                 Image {
                     id: imgNoStickers