emit upload-error from Multipart and Tus

src/plugins/Multipart.js

@@ -73,6 +73,7 @@ export default class Multipart extends Plugin {
       })
 
       xhr.addEventListener('error', (ev) => {
+        this.core.emitter.emit('core:upload-error', file.id)
         return reject('Upload error')
       })
 

src/plugins/Tus10.js

@@ -92,6 +92,7 @@ export default class Tus10 extends Plugin {
 
         onError: (err) => {
           this.core.log(err)
+          this.core.emitter.emit('core:upload-error', file.id)
           reject('Failed because: ' + err)
         },
         onProgress: (bytesUploaded, bytesTotal) => {