Fix Bavaria #269

[XSpielinbox]

🐞 closes #269

@derTobsch would you be ok with leaving Augsburg's special holiday, but moving assumption day up one level to Bavaria as it is applicable to the majority of cities and not only the few that currently exist as more specific cases?

As these non ISO 3166 cities then would have no holidays I have removed them, as I would see ADR 001 as not applicable as there are just to many cities for which I don't see the value to have empty configurations for them.
But if you wish, I could also leave them empty and add empty configurations for other major Bavarian cities.

[derTobsch]

Hey @XSpielinbox, now with the observance type, I would propose the following. We add the assumption day for Bavaria as observance and override them with city configuration with the type public holiday.

[XSpielinbox]

Hey @XSpielinbox, now with the observance type, I would propose the following. We add the assumption day for Bavaria as observance and override them with city configuration with the type public holiday.

@derTobsch Sure, adding it as an observance would be an improvement.
I nevertheless think that one should aim for providing the correct holiday information for most of Bavaria, while keeping the number of subconfigurations at a minimum.

Therefore I see the following options:

1. Declare it a public holiday in complete Bavaria and remove the then useless subconfigurations. This would be correct in 82.9% of the municipalities (Gemeinden), while requiring 0 overrides. This would report public holidays, where there actually are none. This is the behavior this PR currently introduces.
2. Declare it a public holiday in complete Bavaria and introduce overrides for only the major cities that only have it as an Observance: Ansbach, Schwabach, Nürnberg, Fürth, Erlangen, Bayreuth, Coburg and Hof (cities listed with their German name). This would be correct in 83.3% of the municipalities, while requiring 8 overrides. This would report public holidays, where there actually are none, but to a lesser degree.
3. Only have it as an observance in complete Bavaria and introduce overrides for all major cities that have it as a public holiday: Schweinfurt, Würzburg, Bamberg, Aschaffenburg, Weiden in der Oberpfalz, Amberg, Regensburg, Straubing, Passau, Landshut, Ingolstadt, Kempten (Allgäu), Augsburg, München, Kaufbeuren, Memmingen, Rosenheim (cities listed with their German name). This would be correct in 17.9% of the municipalities, while requiring 16 additional overrides (to the one for Augsburg, that exists anyway for their special holiday). This would miss public holidays, where there actually are some, but to a lesser degree.
4. Only have it as an observance in complete Bavaria and remove all subconfigurations that are only there for this holiday and no other purpose. This would be correct in 17.2% of the municipalities, while requiring 0 additional overrides (to the one for Augsburg, that exists anyway for their special holiday). This would miss public holidays, where there actually are some.

Please let me know, which option you would favor. Then I would update the PR accordingly.