Content-Disposition filename gets garbled filename for Japanese Characters in Safari

[ggallotti]

This code :
&HttpResponse.AddHeader(!"Content-Disposition", !'attachment; filename=注文詳細.xlsx')

Gets garbled http download filename in Safari.

Change log:

• We now use RFC5987 " Character Set and Language Encoding for Hypertext Transfer Protocol (HTTP) Header Field Parameters" for encoding filename attribute inside Content-Disposition Header. We fallback to the original method when somethig fails.
• Safari does not support RFC5987 nor String encoded Filename atribute, so we disable encoding for this Browser until RFC5987 get supported.

[genexusbot]

Cherry pick to beta success

• 0257ff0