cubicweb #10669732 binary seems to auto seek at the beginning of stream [rejected]

on file entity after a call to cw_set on data attribute, binary object is seeked to the beginning of the stream

prioritynormal
typebug
done in<not specified>
load0.000
load left0.000
closed by<not specified>
patchadd test to show that binary seek to beginning of stream after cw_set call [in-progress]