organize resources into "Groups"

## User Story

As a user, owner,admin
I want to create separate group to collect all of my web resources
So I am not distracted by resources I am not concerned about.
## Discussion

This feature would allow a single instance of GeoHealthCheck to server multiple stakeholders in a organized fashion within a large organization (such as a government with multiple departments). Adds some enterprise'ness' to it all
## proposal

Provide a hierarchy such as
- Group (eg. an organization or a user)
- Service Type (CSW, FTP)
- Resource (individual web resources)
## Access Control
- allow a user to "admin" a group by adding more group admins or users
- registered users can request to JOIN a group
- visibility of a group may be configurable for viability to everyone, logged in users, group user etc
- allow Groups within groups? eg
- Government of Canada (parent group)
- Environment Canada (sub group)
- Service Type
- Web Resource
- Natural Resources Canada (sub group)
- Service Type
- Web Resource

Es werden keine Dateien, Tests oder Einstiegspunkte genannt. Beginne damit, die vorgeschlagene Gruppenhierarchie, Mitgliedschaft, Sichtbarkeit und die Regeln für verschachtelte Gruppen in einen vereinbarten Umfang zu überführen; als erledigt sollte gelten, dass das definierte Gruppen- und Zugriffskontrollverhalten für die genannten User Stories enthalten ist.

Vom Indexierungsmodell aus dem Issue-Text verfasst.