Update ConsumerConfig to validate use of group.remote.assignor and partition.assignment.strategy based on group.protocol

ConsumerConfig supports both the group.remote.assignor and partition.assignment.strategy configuration options. These, however, should not be used together; the former is applicable only when the group.protocol is set to consumer and the latter when the group.protocol is set to classic. We should emit a warning if the user specifies the incorrect configuration based on the value of group.protocol.