Add linked administrative regions

[ylub]

What does this change

This PR adds linked administrative region methods for the following European locales:

Country	in Faker
Austria	'de_AT'
Czech Republic (Czechia)	'cz_CZ'
Germany	'de_DE'
France	'fr_FR'
Italy	'it_IT'
Poland	'pl_PL'
Slovakia	sk_SK'
Slovenia	'sl_SI'

This is somewhat related to #2383, but adds considerably less weight to faker

What was missing

Several of these locales already included first-level administrative regions, while some also included second-level administrative regions. However, there was no consistent way to generate linked administrative subdivisions where a generated second-level region belongs to a specific first-level region.

How this addresses it

This PR adds methods for working with linked administrative regions:

fake.admin1()	returns a random first-level administrative region.
fake.admin2()	returns a random second-level administrative region.
fake.admin2_from_admin1(admin1)	returns a random second-level administrative region belonging to the specified first-level administrative region.
fake.admin2_with_admin1()	returns a randomly generated second-level administrative region together with its corresponding first-level administrative region.
fake.admin2_w_admin1(admin1)	returns a second-level administrative region together with the specified first-level administrative region.

Administrative region data was sourced from Statoids, Wikipedia's ISO 3166-2 references and administrative subdivision pages, and official government sources where available.

AI Assistance Disclosure (REQUIRED)

• If AI tools were used, I have disclosed which ones, and fully reviewed and verified their output.
  I used ChatGPT for help in finding sources for the information, as well as to fine tune the code and for the fork/pull request.

Checklist

• I have read the documentation about CONTRIBUTING
• I have read the documentation about Coding style
• I have run black instead of make lint and I confirmed consistency.

[ylub]

Hello - just wondering if there's any updates on this PR

Thanks!

[fcurella]

Could you expand on how this PR adds less weight than #2383 ?

I really think we need to come up with some kind of compressed format if we want this to be sustainable.

[ylub]

I was under the impression that these smaller changes were not as heavy as that huge 3000 line one from #2383.

Perhaps the admin regions that already exist in each country's provider could be used as aliases and it would be a matter of adding what is missing as well as the commands that link them