Using an external OIDC provider, add link to user profile in OCIS Account details

[T0mWz]

When you make use of an external user provider / OIDC provider (for example Keycloak or Konnect), then a link to the external user provider in the user account details would be useful. This should then be a configurable option in OCIS & Web.

I have not yet a good description what makes it more clear for a user on the <ocis domain>/account page, but a first impulse;

"You are logged in with an external account provider and can not edit your account details here. Please refer to your (link) to edit your user account."

[wkloucek]

@kulmann I'm moving this issue to Web since this is a UI topic mostly