Verify Group to Fitxer d'Entitats

[Jordi-Miro]

Is your feature request related to a problem? Please describe.
Decidim Barcelona needs a way to automate group verification to avoid manual check of its existence in “Fitxer General d’Entitats de Barcelona”.

Describe the solution you'd like
Decidim should ask the user who creates or modifies the group the information needed to call the Fitxer d’Entitats API.
The way to verify a group should be as similar as possible to the user verification.
Additional context
Here (https://docs.google.com/document/d/1on3sO3oH_eDsryjAXmDYNbJXzc_5c-zqvngDEF-m0Ek/edit?usp=sharing) is the document explaining a possible way to develop the UI.
There are separate API calls to check two kind of entities
• Inscribed in the “Registre d’Entitats de la Generalitat” which have a VAT (NIF) number.
• Non inscribed in the “Registre d’Entitats de la Generalitat” with no VAT number.

Endpoints (DEVELOPMENT)

Crides a grup de fet.
https://fitxer-dentitats.intelligenia.com/services/nfge/fact_group/exists_from_decidim/?id=1&phone=958958958 (Retorna 0)
https://fitxer-dentitats.intelligenia.com/services/nfge/fact_group/exists_from_decidim/?id=1&phone=958958958 (Retorna 2)
https://fitxer-dentitats.intelligenia.com/services/nfge/fact_group/exists_from_decidim/?id=88&phone=95555 (Retorna 1)

Crides a entitats
https://fitxer-dentitats.intelligenia.com/services/nfge/entity/exists_from_decidim/?id=28&phone=958958958 (Retorna 0)
https://fitxer-dentitats.intelligenia.com/services/nfge/entity/exists_from_decidim/?id=28&phone=958555555 (Retorna 2)
https://fitxer-dentitats.intelligenia.com/services/nfge/entity/exists_from_decidim/?id=23338&phone=958555555 (Retorna 1)