oeqa/utils/testexport.py: add functionality for exporting binaries
This new file is encapsulating functionality for both
running tests with binaries support via TestNeedsBin() decorator
and exporting these binaries via testimage.bbclass file.
Addresses [YOCTO #7850], [YOCTO #8478], [YOCTO #8481],
[YOCTO #8536], [YOCTO #8694].
Signed-off-by: Costin Constantin <costin.c.constantin@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
