Logger: Add encoding

[sanderland]

Fix for #6909

Not sure if this can lead to infinite loops.

        except Exception as e:
            Logger.exception("Unexpected exception in logging", e)

[tshirtman]

to be sure, could you write a simple test showing the issue on your machine, and check that the fixed code works with it? bonus points if that's a unittest we can run in CI, that would be most comforting :).

[AndreMiras]

To me, the whole thing should actually be unit tested to show the point.
It shouldn't be that hard to add a test calling the _write_message() method showing that Logger.exception() is then getting called

[AndreMiras]

LGTM, Thanks for unit testing it 💪
Whoever will merge should think about squashing