adding duplicate data filter

[heikoklein]

This PR adds a duplicate filter to pyaro. By default, it filters duplicates of type "stations", "start_times", "end_times", but the user can configure other keys.

This PR starts also using typing-features not available in python 3.9. Following pyaerocom, python 3.9 is therefore no longer supported, and python 3.12 has been added to the list of supported python versions.

closes #22

[avaldebe]

I see a problem on the AutoFilterEngine.supported_filters implementation, which is not part of this PR.

        return self.reader_class().supported_filters()

reader_class returns a generic Reader, which does not require a supported_filters method.

I think that reader_class should returns a AutoFilterReader.

I also see many looks filling up lists across the module, that are cleaner as list comprehensions.
Also, UnkownFilterException is misspell.

[heikoklein]

@avaldebe Thanks for the excellent review. I added nearly all of your suggestions, and concerning typing fixed similar errors in other parts of the code.
I'm not sure if reader_class should use a type-hint returning the abstract base Reader or the implementation AutoFilterReader. The programmer using this code should only work with interface of the basic Reader anyway and not with the specifics of the AutoFilterReader. In python 3.11, this might have been nicer by return -> Self, but for 3.10, I keep the base-class.

[avaldebe]

thanks for addressed the issues I raised

[heikoklein]

Looking again at the AutoFilterEngine base-class and your first comment, I agree with you and return now a AutoFilterReader instead of just a Reader. Sorry for misunderstanding when reading the first time, I got confused since the comment was not related to this PR. I will fix that in #32