Comment 4 for bug 1894801

We cannot pass non-ascii characters directly in cookie values.

A cookie value is a http header value which RFC 7230 Field Value Components [1] specifies:
"Most HTTP header field values are defined using common syntax components (token, quoted-string, and comment) separated by whitespace or specific delimiting characters. Delimiters are chosen from the set of US-ASCII visual characters not allowed in a token (DQUOTE and "(),/:;<=>?@[]{}")."

A solution would be to encode a translated string and decode it before showing it.

[1] https://tools.ietf.org/html/rfc7230#section-3.2.6