scripts: twister: Remove Handler atavisms

Removed following fields from relevant Handlers,
as they were unused in code:

* Handler's state
* Handler's generator
* BinaryHandler's call_west_flash
* QEMUHandler's results
* QEMUWinHandler's results

Signed-off-by: Lukasz Mrugala <lukaszx.mrugala@intel.com>
3 files changed