Support files with unicode names

[geaden]

When files with unicodes names are used in release unicode symobls are converted to underscore. Moreover, files with the same pattern, like か_き_く.pdf and ら_り_ね.pdf are overwritten and only one of the is uploaded.

In interface the name of the file is: ._._..pdf.

The issue is most likely related to cli/cli#8580, however I've seen releases with unicode assets.