[To dev/1.3] [Pipe] Wake parser workers when admission is available

[Caideyipi]

Description

When TsFile parser admission becomes available, processor workers can remain asleep until their next polling interval, delaying pipes behind the fair admission queue. Wake the relevant worker immediately and retain notifications that arrive before the worker begins its idle wait.

Backport of #18843, cherry-picked from aec1ad6139cb4dd1450725f53418cf40c26efb4e to dev/1.3.

• Connect pending parser reservations to their processor worker's wake-up callback and signal the next eligible reservation while preserving fair queue ordering.
• Reuse one memory-budget snapshot during admission checks and expose admission reject/yield counters, a wait timer, and in-flight/waiting gauges.
• Preserve the 1.3 memory-accounting implementation when resolving PipeMemoryManager conflicts, and retain the existing disk-I/O counter when resolving PipeResourceMetrics conflicts.
• Backport regression coverage for notification ordering, notifications before idle wait, 100 waiting pipes, and stop/start behavior.

Validation

• mvn -B -nsu spotless:apply -pl iotdb-core/datanode,iotdb-core/node-commons — passed; no formatting changes.
• mvn -B -nsu test-compile -DskipTests — full reactor passed.
• mvn -B -nsu test-compile -P with-zh-locale -DskipTests — full reactor passed with MAVEN_OPTS="-Xmx2048m -XX:MaxMetaspaceSize=512m"; the initial uncapped attempt exhausted local native memory after DataNode compiled successfully.
• mvn -B -nsu test -pl iotdb-core/datanode -am -Dtest=PipeProcessorSubtaskExecutionGuardTest,PipeProcessorSubtaskWorkerTest,PipeMemoryManagerTest -Dsurefire.failIfNoSpecifiedTests=false -DfailIfNoTests=false — all 18 tests passed, with no failures, errors, or skipped tests.
• git diff --check — passed.

Checklist

• Self-reviewed, including notification ordering and concurrent admission/release.
• Backported unit tests for the changed behavior.