Update our development assets. (#3783)

* Replace downloaded test assets with original content.

* Replace AI generated assets with original content.

* Update preview tests snapshots

* Update UI test snapshots.

---------

Co-authored-by: Stefan Ceriu <stefan.ceriu@gmail.com>

ElementX/Sources/Screens/Timeline/View/TimelineItemViews/VideoRoomTimelineView.swift

@@ -85,8 +85,8 @@ struct VideoRoomTimelineView_Previews: PreviewProvider, TestablePreview {
                 
                 // Blurhash item?
                 
-                VideoRoomTimelineView(timelineItem: makeTimelineItem(caption: "This is a great image 😎"))
+                VideoRoomTimelineView(timelineItem: makeTimelineItem(caption: "This is a great video 😎"))
-                VideoRoomTimelineView(timelineItem: makeTimelineItem(caption: "This is a great image with a really long multiline caption",
+                VideoRoomTimelineView(timelineItem: makeTimelineItem(caption: "This is a great video with a really long multiline caption",
                                                                      isEdited: true))
             }
         }