MINOR: remove unused scala files from core module (#9296)

Reviewers: Mickael Maison <mickael.maison@gmail.com>, Lee Dongjin <dongjin@apache.org>

core/src/main/scala/kafka/common/ClientIdAndTopic.scala

@@ -1,35 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package kafka.common
-
-/**
- * Convenience case class since (clientId, topic) pairs are used in the creation
- * of many Stats objects.
- */
-trait ClientIdTopic {
-}
-
-case class ClientIdAndTopic(clientId: String, topic: String) extends ClientIdTopic {
-  override def toString = "%s-%s".format(clientId, topic)
-}
-
-case class ClientIdAllTopics(clientId: String) extends ClientIdTopic {
-  override def toString = "%s-%s".format(clientId, "AllTopics")
-}
-
-

core/src/main/scala/kafka/common/NoEpochForPartitionException.scala

@@ -1,25 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The ASF licenses this file to You under the Apache License, Version 2.0
- * (the "License"); you may not use this file except in compliance with
- * the License.  You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package kafka.common
-
-/**
- * Thrown when a get epoch request is made for partition, but no epoch exists for that partition
- */
-class NoEpochForPartitionException(message: String) extends RuntimeException(message) {
-  def this() = this(null)
-}