Add norwegian holidays

[eltos]

Closes #174

• Subdivisions:
  • https://www.ssb.no/en/klass/klassifikasjoner/104
  • https://meta.cdq.com/DataModel%3ACDQ/Business_Partner/Address/Country/NO
  • https://www.duden.de/rechtschreibung/Fylke
• Public holidays:
  • https://lovdata.no/dokument/NL/lov/1995-02-24-12 (law on holidays and holiday peace)
  • https://lovdata.no/dokument/NL/lov/1947-04-26-1 (law of 1 and 17 May as holidays)
  • https://www.visitnorway.de/reiseplanung/reisetipps/
  • https://de.visitbergen.com/ideen-and-inspiration/norwegen-entdecken/ferien-und-feiertage-in-norwegen
• School holidays for Agder: https://agderfk.no/vare-tjenester/skole-og-opplaring/opplaring-i-skole/skoledager-ferier-og-fridager/
• School holidays for Akershus: https://afk.no/tjenester/skole-og-opplaring/opplaring-i-skole/skoledager-ferier-og-fridager/
• School holidays for Buskerud: https://bfk.no/tjenester/skole-og-opplaring/opplaring-i-skole/skoledager-ferier-og-fridager/
• School holidays for Finnmark: https://www.ffk.no/tjenester/skole-og-opplaring/opplaring-i-skole-for-elever/skolerute/
• School holidays for Innlandet: https://innlandetfylke.no/tjenester/skole-og-utdanning/opplaring-i-skole/skoleferier-og-fridager/
• School holidays for Møre og Romsdal: https://mrfylke.no/tenester/skole-og-opplaring/opplaring-i-skole/skoleruta/
• School holidays for Nordland: https://www.nfk.no/tjenester/skole-og-opplaring/skoleruta/#faqsporsmal-4623
• School holidays for Oslo: https://www.oslo.kommune.no/skole-og-utdanning/ferie-og-fridager-i-skolen/
• School holidays for Østfold: https://ofk.no/tjenester/skole-og-opplaring/opplaring-i-skole/skoledager-ferier-og-fridager/#faqsporsmal-14677
• School holidays for Rogaland: https://www.rogfk.no/vare-tjenester/skole-og-utdanning/opplaring-i-skole/skoledager-ferier-og-fridager/
• School holidays for Telemark: https://www.telemarkfylke.no/no/skoler/porsgrunn-vgs/meny/elev-ved-porsgrunn-vgs/skolerute/
• School holidays for Troms: https://www.tromsfylke.no/tjenester/skole-og-opplaring/opplaring-i-skole/skolerute/
• School holidays for Trøndelag: https://www.trondelagfylke.no/vare-tjenester/utdanning/elev/skolerute/
• School holidays for Vestfold: https://www.vestfoldfylke.no/no/skoler/kompetansebyggeren/meny/elev-ved-kompetansebyggeren/skolestart-og-skoleruta/skoleruta/
• School holidays for Vestland: https://www.vestlandfylke.no/globalassets/utdanning-og-karriere/elev/skuleruta-2026-2027.pdf