[Dropzone] Accept error messages for a file upload.

[jovertical]

About

Surely, an upload may result to an API error, but those messages aren't fed to the Dropzone component when its all said and done. The component needs that so that it can show it to the consumer.

Todos

• An API error is encountered in User CRUD's uploader when a file uploaded is big enough for the server, use it as a workaround to address this issue.

• In User CRUD's uploader, in cases of file removal, An API error must notify the Dropzone component also, use it as a work around to address this issue.