Fix PathPatternNode wildcard cache lifecycle

[Caideyipi]

Description

PathPatternNode used to retain non-trivial wildcard child names and compile a regular expression on every match. This change caches the compiled Pattern objects instead.

• Compile each non-trivial wildcard pattern when the child is added.
• Reuse the compiled pattern in getMatchChildren.
• Remove cached patterns when children are deleted or cleared, including replacement of an existing wildcard child.
• Include the compiled-pattern cache in memory estimation.
• Reuse the same compilation helper from PathPatternUtil.isNodeMatch.

Testing

mvn spotless:apply -pl iotdb-core/node-commons
mvn -pl iotdb-core/node-commons -Dtest=PathPatternNodeTest test

Result: BUILD SUCCESS; 2 tests passed. Checkstyle and Spotless checks passed.

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This PR has:

• been self-reviewed.
• added comments explaining the intent of the cache.
• added unit tests covering wildcard-cache add, replacement, deletion, and clear paths.

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Key changed/added classes

• PathPatternNode
• PathPatternUtil
• PathPatternNodeTest