Do not swallow Media upload errors

[leandrocp]

A bug in the upload logic might raise errors such as:

[debug] HANDLE EVENT "validate" in Beacon.LiveAdmin.PageLive
  Component: Beacon.LiveAdmin.MediaLibraryLive.UploadFormComponent
  Parameters: %{"_target" => ["asset"]}
[debug] Replied in 374µs
[info] JOINED lvu:0 in 745µs
  Parameters: %{"token" => "[redacted]"}
[debug] failed to call Beacon.MediaLibrary.upload(%Beacon.MediaLibrary.UploadMetadata{site: :my_site, config: %{processor: &Beacon.MediaLibrary.Processors.Image.process!/1, providers: [Beacon.MediaLibrary.Provider.Repo], validations: []}, allowed_media_accept_types: ["image/jpeg", "image/gif", "image/png", "image/webp", ".pdf"], path: "/tmp/plug-1730-HXLr/live_view_upload-1730156638-779982521169-1", name: "IMG_9166.jpg", media_type: "image/jpeg", size: 253356, output: nil, resource: #Ecto.Changeset<action: nil, changes: %{}, errors: [], data: #Beacon.MediaLibrary.Asset<>, valid?: true, ...>, extra: nil}) for site :my_site on node :nonode@nohost
[error] GenServer #PID<0.1757.0> terminating
** (Beacon.LiveAdmin.ClusterError) failed to call Beacon.MediaLibrary.upload(%Beacon.MediaLibrary.UploadMetadata{site: :my_site, config: %{processor: &Beacon.MediaLibrary.Processors.Image.process!/1, providers: [Beacon.MediaLibrary.Provider.Repo], validations: []}, allowed_media_accept_types: ["image/jpeg", "image/gif", "image/png", "image/webp", ".pdf"], path: "/tmp/plug-1730-HXLr/live_view_upload-1730156638-779982521169-1", name: "IMG_9166.jpg", media_type: "image/jpeg", size: 253356, output: nil, resource: #Ecto.Changeset<action: nil, changes: %{}, errors: [], data: #Beacon.MediaLibrary.Asset<>, valid?: true, ...>, extra: nil}) for site :my_site on node :nonode@nohost

Got:

  no function clause matching in Image.Error.exception/1

But as reported "the net result of this error is that the page reloads without showing success or failure, and the image is not listed. No error is reported to the user interface in the live admin screens" which should not be the behavior, we should be explicit that something out of ordinary happened and give some feedback to users.