New check which find duplicate except clauses

[kasium]

flake8-bugbear already find duplicate exeptions in the same tuple, but across different except's this is not done

Examples:

try:
    pass
except ValueError:
    pass
except ValueError:
    pass

try:
    pass
except (ValueError, TypeError):
    pass
except (ValueError, UnicodeError):
    pass

I'm happy tp contribute this check 😄

[cooperlees]

I guess this is doable, so sure, would accept this. Should be easy to make not noisey.

Please add description to README and add unit tests for the new checks please for it to be accepted.

[kasium]

Thanks for your comment. Let me give it a try

[cooperlees]

Released in 22.9.11