Add specific school presets for the DE

[tordans]

This is based on openstreetmap#1021. Thanks for the inspiration to solve this like you did, @arch0345.

I reused the school and isced level presets and fields from openstreetmap#1021 whenever possible. It will be important to add the correct translations during the translation process

• school/1-US,DE.json => "Grundschule"
• school/2-US,DE.json => "Sekundarschule ohne Oberstufe"
  • terms: "Sekundarstufe I", "Mittelstufe"
  • More terms via https://wiki.openstreetmap.org/wiki/DE:Key:isced:level#Werte_f.C3.BCr_D-A-CH
  • Local terms for "Bundesländer" at https://de.wikipedia.org/wiki/Schulsystem_in_Deutschland#Sekundarstufe_I, eg. "Stadtteilschule"
• school/2-DE.json => "Sekundarschule mit Oberstufe"
  • terms: "Sekundarstufe II", "Oberstufe"
  • More terms via https://wiki.openstreetmap.org/wiki/DE:Key:isced:level#Werte_f.C3.BCr_D-A-CH

The ISCED level fields work nicely with the multiCombo by automatically selecting the right preset based on the field combinations.

Right now this PR is based on https://github.com/arch0345/id-tagging-schema/tree/us-schools to make comparing changes easier with openstreetmap#1021. I suggest to merge openstreetmap#1021 first and then change the base in this PR to openstreetmap:main.

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This is a fresh take on and supersedes openstreetmap#331

[tordans]

Oh, I see now that I created a PR against https://github.com/arch0345/id-tagging-schema, that was not my intention … but makes sense :-)

@arch0345 you could either merge this and we propose it as a shared PR in openstreetmap/id-tagging-schema or I will wait until your PR is merged and create a new PR against openstreetmap/id-tagging-schema then…