KAFKA-19681 Optimize MetadataShell tool find command print warning message intead of throwing exception

[m1a2st]

When using the find command, it currently lists all directories and
files. However, if it cannot find a child node, it throws an exception
and prevents the subsequent directories from being printed. I think we
should change this behavior to print an error message instead of
throwing an exception, which would be more user-friendly.

In addition, since zkMigrationState is not used in Kafka 4.X, we should
remove this child node. This was missed in this
772aa24

Trunk:

>> find
.
// skip
./image/features/metadataVersion
Unexpected error: Expected zkMigrationState to be a valid child of
./image/features, but it was not.
java.lang.RuntimeException: Expected zkMigrationState to be a valid
child of ./image/features, but it was not.
        at
org.apache.kafka.shell.command.FindCommandHandler.find(FindCommandHandler.java:115)
        at
org.apache.kafka.shell.command.FindCommandHandler.find(FindCommandHandler.java:118)
        at
org.apache.kafka.shell.command.FindCommandHandler.find(FindCommandHandler.java:118)
        at
org.apache.kafka.shell.command.FindCommandHandler.lambda$run$0(FindCommandHandler.java:98)
        at
org.apache.kafka.shell.glob.GlobVisitor.accept(GlobVisitor.java:115)
        at
org.apache.kafka.shell.glob.GlobVisitor.accept(GlobVisitor.java:103)
        at
org.apache.kafka.shell.command.FindCommandHandler.run(FindCommandHandler.java:102)
        at
org.apache.kafka.shell.InteractiveShell.runMainLoop(InteractiveShell.java:113)
        at
org.apache.kafka.shell.MetadataShell.run(MetadataShell.java:169)
        at
org.apache.kafka.shell.MetadataShell.main(MetadataShell.java:226)

This branch if not find that node:

// skip
./image/features/metadataVersion
Expected zkMigrationState to be a valid child of ./image/features, but
it was not.
./image/producerIds
./image/producerIds/nextProducerId
./image/provenance
./image/scram
./image/scram/SCRAM-SHA-256
// skip