Regression fixes: --hidraw option, python3, hidpp10

After a recent refactoring, the `--hidraw` option was gone from `solaar-cli`. One included patch allows the CLI version of Solaar to make use of `--hidraw` again, the GUI did not, (and still does not) support this option (at the moment?).

One python3 fix is added (again) for solaar-cli and another refactoring mistake has been corrected.