fix: meaningful error when authentication fails

[maiminhp]

Fixes #83

Example error:

$ python groups.py 
Traceback (most recent call last):
  File "/home/<redacted>/Spond/groups.py", line 33, in <module>
    asyncio.run(main())
  File "/usr/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/home/<redacted>/Spond/groups.py", line 14, in main
    groups = await s.get_groups()
  File "/home/<redacted>/Spond/spond/spond.py", line 60, in wrapper
    raise e
  File "/home/<redacted>/Spond/spond/spond.py", line 57, in wrapper
    await self.login()
  File "/home/<redacted>/Spond/spond/spond.py", line 41, in login
    raise AuthenticationError(err_msg)
spond.spond.AuthenticationError: Login failed. Response received: {'errorKey': 'wrongEmailOrPassword', 'message': 'Wrong email or password.'}

[elliot-100]

Thanks for this @ptmminh.

I think the ValueError should be a more specific AuthenticationError.

e.g.

class AuthenticationError(Exception)
  pass
...
raise AuthenticationError(err_msg)

I don't know enough about aiohttp to work out the 'Unclosed connector' problem, but can be dealt with separately; this pull request delivers value without it.

[Olen]

Since the login now raises an exception, this exception should be caught by the functons that calls the login function.

To close the connector, all you need to do is catch the exception and do someting like

    except AuthenticationError:
        print("Authentication error")
        await s.clientsession.close()
        sys.exit()

[maiminhp]

Thanks @elliot-100 and @Olen for the review! All very helpful remarks, I've made adjustments based on your suggestions. Now the connector even closes (see example trace stack above as proof).

I also created a decorator to handle the authentication check to avoid duplicated code in each method that calls login.

Also quite new to this repo, I usually rebased interactively to keep main clean and forced push after but happy to follow whatever convention you currently have and what's easiest for you to review.

[Olen]

Great work.
The repo and workflows could probably be improved. It was just my personal little thing for a long time, but with more contributions more structure would be good.

@elliot-100 already made a lot of improvements in this regard, and I am grateful for that.

[Olen]

It even passes the new test-script @elliot-100 just added.