spring-kafka: ser/de

[osoykan]

This pull request includes several changes to improve the serialization mechanism and enhance the Spring Kafka testing infrastructure. It is one of the works that need to be done to improve serialization support when users want to use Protobuf, Avro, JSON(already supported), and other serialization systems.

Most notable change is the change for TestSystemKafkaInterceptor<*,*>. The dependency for this class was an ObjectMapper instance that you can provide through bean provider/Spring-Boot DI, but now it relies on StoveSerde<T, K> interface, hence users can replace it with their ser/de choices. I have written a test to prove the approach is working, take a look, ProtobufSerdeKafkaSystemTest.kt.

Improvements to serialization mechanism:

• examples/spring-example/src/test/kotlin/com/stove/spring/example/e2e/TestSystemInitializer.kt: Added StoveSerde.jackson.anyByteArraySerde() bean to the test system dependencies.
• gradle/libs.versions.toml: Updated the kotlinx-serialization library to include json and protobuf modules. [1] [2]
• lib/stove-testing-e2e/build.gradle.kts: Changed the kotlinx.serialization dependency to kotlinx.serialization.json.

Enhancements to Kafka testing infrastructure:

• starters/spring/stove-spring-testing-e2e-kafka/build.gradle.kts: Added Protobuf plugin and related dependencies for Kafka streams. [1] [2]
• starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/Extensions.kt: Replaced ObjectMapper with StoveSerde for message serialization.
• starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/KafkaSystem.kt: Added support for Kafka admin operations and improved the message publishing mechanism using StoveSerde.

Codebase simplifications:

• examples/spring-streams-example/build.gradle.kts: Replaced kafka-streams.registry with kafka-streams.protobuf.serde.
• starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/MessageStore.kt: Updated the MessageStore class to use simplified message types.

Adresses #560

[github-actions[bot]]

Code Coverage

File	Coverage [79.43%]	:x:
starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/Extensions.kt	100.00%	:white_check_mark:
starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/KafkaSystem.kt	77.14%	:x:
starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/MessageStore.kt	71.43%	:x:
starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/Options.kt	93.33%	:white_check_mark:
starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/StoveMessage.kt	44.00%	:x:
starters/spring/stove-spring-testing-e2e-kafka/src/main/kotlin/com/trendyol/stove/testing/e2e/kafka/TestSystemInterceptor.kt	91.89%	:white_check_mark:

Total Project Coverage	71.41%	:x:

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 59.85915% with 57 lines in your changes missing coverage. Please review.

Project coverage is 82.21%. Comparing base (2043ba4) to head (9858527). Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
...m/trendyol/stove/testing/e2e/kafka/StoveMessage.kt	33.33%	28 Missing :warning:
...om/trendyol/stove/testing/e2e/kafka/KafkaSystem.kt	63.46%	17 Missing and 2 partials :warning:
...l/stove/testing/e2e/kafka/TestSystemInterceptor.kt	71.42%	3 Missing and 3 partials :warning:
...com/trendyol/stove/testing/e2e/kafka/Extensions.kt	86.66%	0 Missing and 2 partials :warning:
...m/trendyol/stove/testing/e2e/kafka/MessageStore.kt	66.66%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #658 +/- ## ========================================== - Coverage 83.14% 82.21% -0.93% ========================================== Files 85 85 Lines 2462 2508 +46 Branches 143 161 +18 ========================================== + Hits 2047 2062 +15 - Misses 316 346 +30 - Partials 99 100 +1 ```

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