[Video] Upload errors and UI improvements (#5092)

* surface errors in UI

* style progress indicator

* remove job status progress

* rm log

* fix webm ext

src/lib/media/video/errors.ts

@@ -4,3 +4,10 @@ export class VideoTooLargeError extends Error {
     this.name = 'VideoTooLargeError'
   }
 }
+
+export class ServerError extends Error {
+  constructor(message: string) {
+    super(message)
+    this.name = 'ServerError'
+  }
+}