Hide EventImage bubbles on hover

TODO.md

@@ -14,6 +14,7 @@
   - Video: missing buttons and small size problems
   - Audio: online playback is buggy, must download+play file
   - EventLink
+    - Special treatment for matrix.to URLs?
   - EventFile & Downloading (right click on media > save as...)
 
 - Refactoring

src/qml/Chat/Timeline/EventImage.qml

@@ -85,6 +85,10 @@ HMxcImage {
         anchors.top: parent.top
         text: loader.showSender
         textFormat: Text.StyledText
+        opacity: hover.hovered ? 0 : 1
+        visible: opacity > 0
+
+        Behavior on opacity { HNumberAnimation {} }
     }
 
     EventImageTextBubble {
@@ -92,5 +96,9 @@ HMxcImage {
         anchors.bottom: parent.bottom
         text: [loader.showDate, loader.showLocalEcho].join(" ").trim()
         textFormat: Text.StyledText
+        opacity: hover.hovered ? 0 : 1
+        visible: opacity > 0
+
+        Behavior on opacity { HNumberAnimation {} }
     }
 }