[cleanup][test] Remove PortManager and use kernel-assigned ports everywhere

[merlimat]

Motivation

PortManager (in pulsar-common) and the inner BasePortManager of LocalBookkeeperEnsemble allocated "free" ports via ServerSocket(0) and tracked them in a JVM-level lock set. The lock was JVM-only, so the OS-level port could still be grabbed by another process between allocation and bind, producing flaky BindExceptions in tests (most recently ShadowTopicRealBkTest.setup).

The class has outlived its usefulness — modern BookKeeper identifies bookies by bookieId, not host:port, so kernel-assigned ports (port 0) work across the board. The "lock" never actually prevented OS-level collisions anyway.

Modifications

Removed

• pulsar-common/.../PortManager.java and its test.
• pulsar-package-management/.../test/PortManager.java (unused duplicate).
• BasePortManager inner class in LocalBookkeeperEnsemble.
• All bkBasePort constructor variants of LocalBookkeeperEnsemble.
• The Supplier<Integer> portManager parameter from LocalBookkeeperEnsemble — every caller was passing () -> 0. Bookies now always bind to kernel-assigned ports internally.
• --bookkeeper-port CLI option from pulsar standalone (and its setter, getter, builder method, plus the test calls). Multi-bookie standalone gets kernel-assigned ports.
• useDynamicBrokerPorts() toggle in MultiBrokerBaseTest (now always dynamic).
• bkPort field in BKCluster.BKClusterConf.

Refactored

• BKCluster: bookies bind to port 0; bookieId is derived from the data dir hash so multiple cluster instances on a shared metadata store don't collide on cookie validation, while restarts on the same dir keep cookies stable. The unused cookie-parsing port-recovery logic is dropped.
• MultiBrokerBaseTest: mainBrokerPort and additionalBrokerPorts are populated post-start from pulsar.getBrokerListenPort() instead of pre-allocated.
• PulsarTestContext.handlePreallocatePorts: inlined ServerSocket(0) allocation. Still needed by tests that build advertised-listener URLs before the broker starts (those URLs require a known port up front).
• 17 test files updated: PortManager.nextLockedFreePort() calls replaced with 0 (let kernel pick) or inline ServerSocket(0) (only where pre-allocation is genuinely required, e.g. for advertised-listener URLs).
• PulsarStandaloneTest.testStandaloneWithRocksDB: assertion switched from getBookiePort() (now returns kernel-assigned ports that change per restart) to getBookieId() (the persistent BK identity).

Behavior change

--bookkeeper-port is gone from pulsar standalone. Bookies get kernel-assigned ports — no impact for normal usage since clients only connect to the broker, not directly to bookies.

Verifying this change

Locally exercised the affected tests:

• LocalBookkeeperEnsembleTest (2/2)
• ShadowTopicRealBkTest (1/1)
• PulsarStandaloneTest (5/5)
• EndToEndTest for BKCluster (10 passed, 1 skipped)
• AdvertisedListenersTest, LoadManagerFailFastTest, AdvertisedListenersMultiBrokerLeaderElectionTest

Full compileJava and compileTestJava clean.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API: removes --bookkeeper-port CLI option from pulsar standalone
• The schema: no
• The default values of configurations: no
• The threading model: no
• The binary protocol: no
• The REST endpoints: no
• The admin CLI options: --bookkeeper-port removed from pulsar standalone
• The metrics: no
• Anything that affects deployment: no