Replace DomainNegotiator with DomainNegotiationContext wherever possible

The DomainNegotiator service can be replaced by the newly introduced DomainNegotiationContext almost everywhere except in the DomainSubscriber service which handles the default domain negotiation in a kernel request event handler.

This will help significantly reduce the risk of circular dependency errors as the DomainNegotiationContext service is a simple object without dependencies nor custom logic.