cubicweb #841062 Review use of NamedTemporaryFile in the CW codebase [deprecated]

Quoting the tempfile documentation:

Whether the name can be used to open the file a second time, while the named temporary file is still open, varies across platforms (it can be so used on Unix; it cannot on Windows NT or later).

Using this function can cause problems when we try to run the cubicweb tests under windows.

Files requiring check:

done in<not specified>
load left0.000
closed by<not specified>