[Task]: [Avro] Use "extensions/avro" instead of avro from"core" in Java SDK modules

[aromanenko-dev]

What needs to happen?

Once Avro support is extracted into a dedicated module extensions/avro, then all Beam Java SDK modules have to switch to use it instead of avro-related classes from "core".

Affected packages:

• org.apache.beam.examples
• org.apache.beam.runners.dataflow
• org.apache.beam.sdk.extensions.sql
• org.apache.beam.sdk.io.gcp
• org.apache.beam.sdk.io.kafka
• org.apache.beam.sdk.io.parquet
• org.apache.beam.sdk.nexmark

Issue Priority

Priority: 2 (default / most normal work should be filed as P2)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner

[Abacn]

Note that some changes related to avro in core happened after #24293 was in such as #24756. Need to synchronize the core avro and extension avro as part of this task.

[aromanenko-dev]

@Abacn Thanks! I applied these changes on extensions/avro at #24854