[FLINK-34251][core] ClosureCleaner to include reference classes for non-serialization exception

[liuml07]

This is a revised version of the previous (auto-)closed PR #24205
More discussions in the JIRA: https://issues.apache.org/jira/browse/FLINK-34251

What is the purpose of the change

Currently the ClosureCleaner throws exception if {{checkSerializable} is enabled while some object is non-serializable. It includes the non-serializable (nested) object in the exception in the exception message.

However, when the user job program gets more complex pulling multiple operators each of which pulls multiple 3rd party libraries, it is unclear how the non-serializable object is referenced as some of those objects could be nested in multiple levels. For example, following exception is not straightforward where to check:

org.apache.flink.api.common.InvalidProgramException: java.lang.Object@528c868 is not serializable. 

It would be nice to include the reference stack in the exception message, as following:

org.apache.flink.api.common.InvalidProgramException: java.lang.Object@72437d8d is not serializable.
Referenced via [com.mycompany.myapp.ComplexMap -> com.mycompany.myapp.LocalMap -> 
com.yourcompany.yourapp.YourPojo -> com.hercompany.herapp.Random -> java.lang.Object]

Verifying this change

This change is largely covered by existing tests, and new test case was added to ClosureCleanerTest.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (yes / no)
• The serializers: (yes / no / don't know)
• The runtime per-record code paths (performance sensitive): (yes / no / don't know)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (yes / no / don't know)
• The S3 file system connector: (yes / no / don't know)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[liuml07]

Could you review this, @davidradl ? Thanks

[flinkbot]

CI report:

• 9bdfc07 Azure: SUCCESS

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[davidradl]

nits: this looks useful. I have some comments in case they are useful for you. You do not need to act on them.

• I wonder about the use of -> as the classes could have children so a list does not necessarily represent the branching. Would it be worth using , as the separator?
• I assume it is not just the class but also the value that could cause this to be not able to be serialized.. It might be that we have values with the same type at different locations in the children. I do not know how hard these issues are to debug; we could use the declared fields to serialize the object child by child to find out which one is
  not serializing?

[afedulov]

@gyfora if I recall correctly we ran into exactly the issue addressed by this PR in the Operator code. Could you please take a look?