Add OpenBuilder.withKeepUpdateMetadata and DeleteBuilder.withLoggerContext to the builder API

[merlimat]

Descriptions of the changes in this PR:

Follow-up to BP-69 (#4766), which added CreateBuilder.withLoggerContext / OpenBuilder.withLoggerContext so applications can attach their slog logging context to created/opened ledgers.

Motivation

Two gaps block applications (specifically Apache Pulsar) from carrying application logging context on all ledger operations through the builder API:

1. Only the classic callback API BookKeeper.asyncOpenLedger(lId, digestType, passwd, cb, ctx, keepUpdateMetadata) can set keepUpdateMetadata. Pulsar's recovery-open call sites (ManagedLedgerImpl initialize, ManagedCursorImpl cursor recovery, BookkeeperSchemaStorage / CompactedTopicImpl / BookkeeperBucketSnapshotStorage opens) all pass keepUpdateMetadata=true, so they cannot migrate to the builder API and therefore cannot use withLoggerContext.
2. DeleteBuilder had no withLoggerContext, so deletes could not carry application context.

Changes

OpenBuilder.withKeepUpdateMetadata(boolean) (first commit)

• New default method returning this on the @Public/@Unstable interface, keeping source compatibility for out-of-tree implementors (same approach as withLoggerContext).
• OpenBuilderBase stores the flag; LedgerOpenOp.OpenBuilderImpl calls initiateWithKeepUpdateMetadata() when the flag is set on a recovery open. The flag only has an effect for recovery opens — non-recovery opens always register the metadata listener immediately — matching the classic API, which only exposes the flag on the recovery-open overload.
• Tests in BookKeeperBuildersTest verify the ledger metadata listener is registered when opening with recovery and the flag set, and not registered without it.

DeleteBuilder.withLoggerContext(Logger) (second commit)

• New default no-op method mirroring BP-69's CreateBuilder/OpenBuilder support.
• DeleteBuilderImpl passes the parent logger to LedgerDeleteOp, whose logger is now a per-op contextual logger (parent context via slog's LoggerBuilder.ctx(Logger) plus the always-present ledgerId attribute), like LedgerOpenOp. The lombok @CustomLog static logger moved to DeleteBuilderImpl, its only remaining user (builder validation runs before an op exists).
• One behavioral addition: delete failures are now logged at debug level through the contextual logger — the delete path previously had no per-op log statements, so the context would have had nothing to ride on. Failures keep being reported to the caller via the callback, and debug level keeps the log silent at default levels (double deletes are routine for some applications).
• LoggerContextTest gains the DeleteBuilder chain and null-is-no-op tests, plus a deterministic check that a failed delete's debug event carries the parent logger's attributes and the ledgerId.

Verified with BookKeeperBuildersTest (31 tests) and LoggerContextTest (8 tests), and checkstyle:check — all green.