Add SHOW RECEIVERS support

[Caideyipi]

Summary

• add tree-model SHOW RECEIVERS and table-model information_schema.receivers support
• track active pipe receiver sessions, sender endpoints, pipe IDs, handshake/transfer timestamps, and request counts
• wire DataNode/ConfigNode thrift and air-gap receiver runtime recording

Tests

• mvn "-Ddevelocity.off=true" -pl iotdb-core/node-commons -Dtest=PipeReceiverRuntimeRegistryTest test
• mvn "-Ddevelocity.off=true" -DskipTests compile -pl iotdb-core/antlr,iotdb-core/relational-grammar,iotdb-core/node-commons,iotdb-core/confignode
• mvn "-Ddevelocity.off=true" -DskipTests spotless:check -pl iotdb-core/node-commons,iotdb-core/datanode,iotdb-core/confignode,iotdb-core/relational-grammar,iotdb-core/antlr
• git diff --check

Notes

• DataNode focused compile is still blocked by unrelated generated Freemarker/calc symbols such as IFill, LinearFill, Accumulator, ComparatorChain, and IoTDBConfig.getModeMapSizeThreshold().
• ConfigNode receiver records proxied through DataNode use receiver_node_id = -1 because the current proxy path does not expose the exact target ConfigNode id.