[KYUUBI #7149] feat: Add shutdown watchdog to forcefully terminate the spark engine and prevent resource leaks. by wangzhigang1999 · Pull Request #7150

[KYUUBI #7149] feat: Add shutdown watchdog to forcefully terminate the spark engine and prevent resource leaks. by wangzhigang1999 · Pull Request #7150 · apache/kyuubi

- Added a new module `kyuubi-spark-shutdown-watchdog` to monitor and manage the graceful shutdown of Spark SQL engines.
- Implemented configuration options for enabling the watchdog and setting timeout values.
- Updated documentation to include usage instructions and configuration details for the new feature.
- Removed the previous `ThreadDumpUtils` from `kyuubi-common` as its functionality is now encapsulated within the new module.
- Added unit tests to ensure the watchdog operates correctly under various scenarios.

- Added a new module `kyuubi-spark-shutdown-watchdog` to monitor and manage the graceful shutdown of Spark SQL engines.
- Implemented configuration options for enabling the watchdog and setting timeout values.
- Updated documentation to include usage instructions and configuration details for the new feature.
- Removed the previous `ThreadDumpUtils` from `kyuubi-common` as its functionality is now encapsulated within the new module.
- Added unit tests to ensure the watchdog operates correctly under various scenarios.

…into branch-spark-engine-terminator

# Conflicts:
#	extensions/spark/kyuubi-spark-shutdown-watchdog/pom.xml
#	extensions/spark/kyuubi-spark-shutdown-watchdog/src/main/java/org/apache/spark/kyuubi/shutdown/watchdog/SparkShutdownWatchdogPlugin.java
#	extensions/spark/kyuubi-spark-shutdown-watchdog/src/main/java/org/apache/spark/kyuubi/shutdown/watchdog/ThreadDumpUtils.java

…g and documentation

- Changed artifact ID in `pom.xml` to remove Scala version suffix for consistency.
- Updated documentation to clarify building and usage instructions, including timeout configuration.
- Adjusted test scripts to reflect new artifact naming conventions.
- Enhanced code readability and maintainability by simplifying the watchdog thread initialization and configuration handling.
- Added test-only helper method to check if the watchdog is running.