[Pipe] Add SHOW PIPE MEMORY for named memory blocks

[Caideyipi]

Description

Named Pipe memory blocks

• Add an immutable name to every PipeMemoryBlock managed by PipeMemoryManager.
• Propagate descriptive names through all Pipe memory allocation APIs and call sites.
• Keep live zero-sized blocks visible until release, while using weak references so diagnostics do not retain otherwise unreachable zero-sized blocks.
• Preserve one output row per block instance; blocks with the same name are not aggregated.

SHOW PIPE MEMORY and information_schema

• Add SHOW PIPE MEMORY in the table SQL dialect.
• Add information_schema.pipe_memory with:
  • name STRING TAG
  • memory_usage_in_bytes INT64 ATTRIBUTE
• Expose floating memory as an independent FloatingMemory block.
• Read the table from the local DataNode and require global system privilege.

Tests

• Add parser and PipeMemoryManager unit coverage.
• Update IoTDBDatabaseIT for table discovery, schema, permissions, SHOW/SELECT access, and system-table counts.
• Verified:
  • mvn -o install -pl iotdb-core/node-commons,iotdb-core/relational-grammar -DskipTests
  • mvn -o test -pl iotdb-core/datanode -Dtest=ShowPipeMemoryTest,PipeMemoryManagerResizeTest,LoadTsFileMemoryManagerTest -Dcheckstyle.skip=true -Dspotless.check.skip=true
  • mvn checkstyle:check -pl iotdb-core/datanode
  • git diff --check

The integration test module could not be executed locally in offline mode because several required snapshot artifacts were unavailable.

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This PR has:

• been self-reviewed.
  • concurrent read and write
• added comments explaining non-obvious lifecycle and accounting behavior.
• added unit tests or modified existing tests to cover new code paths.
• added integration tests.

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Key changed/added classes

• PipeMemoryBlock
• PipeMemoryManager
• InformationSchema
• InformationSchemaContentSupplierFactory
• RelationalSql.g4
• AstBuilder
• IoTDBDatabaseIT