[FLINK-11015] Remove deprecated code for format-specific Kafka table …

…connectors

This commit removes all classes and methods that have been deprecated in
Flink 1.6 for separating Kafka connectors from Avro and JSON formats.

This closes apache#7182.

flink-connectors/flink-connector-kafka-0.10/pom.xml

@@ -86,40 +86,8 @@ under the License.
  <optional>true</optional>
  </dependency>
 
- <dependency>
- <groupId>org.apache.flink</groupId>
- <artifactId>flink-avro</artifactId>
- <version>${project.version}</version>
- <!-- Projects depending on this project, won't depend on flink-avro. -->
- <optional>true</optional>
- </dependency>
-
- <dependency>
- <groupId>org.apache.flink</groupId>
- <artifactId>flink-json</artifactId>
- <version>${project.version}</version>
- <!-- Projects depending on this project, won't depend on flink-json. -->
- <optional>true</optional>
- </dependency>
-
  <!-- test dependencies -->
 
- <dependency>
- <groupId>org.apache.flink</groupId>
- <artifactId>flink-avro</artifactId>
- <version>${project.version}</version>
- <scope>test</scope>
- <type>test-jar</type>
- </dependency>
-
- <dependency>
- <groupId>org.apache.flink</groupId>
- <artifactId>flink-json</artifactId>
- <version>${project.version}</version>
- <type>test-jar</type>
- <scope>test</scope>
- </dependency>
-
  <dependency>
  <groupId>org.apache.flink</groupId>
  <artifactId>flink-streaming-java_${scala.binary.version}</artifactId>