[Backport 7.9] - No error message when uploading large images in image picker

When uploading a large image using the upload functionality in the image picker (top left in the dialog window), no error message is shown. An error message should indicate to the user that the image is too large (due to resolution or file-size), similarly to the error message that is shown when uploading large images via the image gallery/tab.

Reproduction path:
-Open the images picker (either by opening a document containing an image field, or a rich-text field (click on add image in CKEditor))
-Upload an image of at least 5MB (or whatever the limit on your env is)
-The image will upload, the picker refreshes but no image has been stored to the repository and no error message is shown

Expected behaviour:
-Show error message after uploading, similarly to when uploading an image via the Images tab