file-xfer: Fix bad filename encoding
file-xfer: Fix bad filename encoding

Manual for G_FILE_ATTRIBUTE_STANDARD_NAME states:
 > The name is the on-disk filename which may not be in any known
 > encoding, and can thus not be generally displayed as is.

Considering a file named "ěščřžýáíé", if we use
G_FILE_ATTRIBUTE_STANDARD_NAME to get the file name, we will have the
following 72 bytes long string:
"\xc4\x9b\xc5\xa1\xc4\x8d\xc5\x99\xc5\xbe\xc3\xbd\xc3\xa1\xc3\xad\xc3\xa9"

This is a regression introduced at 4647ac9a2a72c98b6841180ccf5f8d

Possible solutions are:
1) Using G_FILE_ATTRIBUTE_STANDARD_DISPLAY_NAME attribute;
2) Using g_file_info_get_attribute_byte_string() function;
3) Using the g_file_get_basename() which was used before 4647ac9a2a72c9

Using option 2 based on better long term solution.
This give us the correct 18 bytes long utf-8 string to "ěščřžýáíé"

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1440206
Signed-off-by: Victor Toso <39b7599ff73bbf5db531748ba5250f21fa7120ff@redhat.com>
Acked-by: Christophe Fergeau <05b95054a663c388a4e33d95828cb30f0370f8ef@redhat.com>

flexVDI/spice-gtk,flexVDI/spice-gtk,fgouget/spice-gtk,fgouget/spice-gtk,fgouget/spice-gtk