Offer download of video recording backups if they are available

Remove them, independently if they were downloaded or not.

src/components/mini-widgets/MiniVideoRecorder.vue

@@ -118,6 +118,16 @@ onBeforeMount(async () => {
     }
   }
   addScreenStream()
+
+  const videoKeys = await cockpitVideoDB.keys()
+  videoKeys.forEach(async (savedVideoName) => {
+    const videoBlobArray: Blob[] = (await cockpitVideoDB.getItem(savedVideoName)) as Blob[]
+    const blob = videoBlobArray.reduce((a, b) => new Blob([a, b], { type: 'video/webm' }))
+    fixWebmDuration(blob, Date.now() - timeRecordingStart.value.getTime()).then((fixedBlob) => {
+      saveAs(fixedBlob, savedVideoName)
+    })
+    await cockpitVideoDB.removeItem(savedVideoName)
+  })
 })
 
 const toggleRecording = async (): Promise<void> => {