Prevent same localized names when uploading images/assets

CMS7-3604 fixed the same-name siblings issue when uploading image and asset files. However it does not aware of localized names duplication.

Reproduction path:

1. Open hippo-go-green
2. Upload an image file lion.jpeg.
3. Open the upload image, rename its url to "lion1.jpeg"
4. Upload the image "lion.jpeg" again to the same folder.

Result: two images in the same folder, both have the display (localized) names "lion.jpeg" but have different url names: "lion.jpeg" and "lion1.jpeg".

Expect: the uploading dialog should prevent creating the later image by a warning message.