Mapping user groups to teams

[ihard]

Now it is possible to specify the x-webauth-user: user1 header and the user will be created.
I would also like to be able to place a user in the desired teams based on his group membership.
Groups can be passed in the x-webauth-teams header: moira_team1, moira_team2 - upon receiving such a header, the user will immediately be assigned to teams team1 and team2 - as an example.

For OIDC, groups are usually transmitted in the standard scope: groups , the data can be easily retrieved by an authorization proxy and inserted into the x-webauth-teams/x-webauth-groups header

For flexibility, it is proposed to make a configurable mapping of groups from the header to command identifiers, as an example:

teams:
    - id: team1
      group: moira_team1
    - id: team2
      group: moira_team2