Bulk load previously required SHARD_ENCODE_LOCATION_METADATA to be enabled,
which pulled in the entire DataMoveMetaData persistence machinery. This was
unnecessary overhead — the BulkLoadTaskState is already independently persisted
at bulkLoadTaskKeys (keyed by range), and the storage server already knows its
range when fetching keys.

The core change: SS now looks up bulk load task metadata directly by range from
bulkLoadTaskKeys, instead of the old indirection path:
  dataMoveId → DataMoveMetaData → BulkLoadTaskState

Changes by component:

Storage Server (storageserver.actor.cpp):
- Replace getBulkLoadTaskStateFromDataMove() with getBulkLoadTaskStateByRange()
  in both fetchKeys and fetchShard paths
- Remove the gate that disabled conductBulkLoad when dataMoveId was
  anonymousShardId or invalid
- Remove assertions that cross-checked dataMoveId against the task state

Data Distributor (DDRelocationQueue.actor.cpp, DataDistribution.cpp/.h):
- When SHARD_ENCODE_LOCATION_METADATA is off, generate a proper dataMoveId
  with LOGICAL_BULKLOAD encoded for bulk load tasks (instead of anonymousShardId)
- Add bulk load task validation and dataMoveId assignment path that runs
  without SHARD_ENCODE_LOCATION_METADATA
- Remove the bulkLoadIsEnabled() gate that required SHARD_ENCODE_LOCATION_METADATA
- Remove the DDBulkLoadModeMonitorSkipped early return

MoveKeys (MoveKeys.cpp):
- Add optional dataMoveId parameter to startMoveKeys and finishMoveKeys
- When a valid dataMoveId is present, write serverKeysValue(dataMoveId) instead
  of serverKeysTrue — this encodes the LOGICAL_BULKLOAD type so SS can decode it
- Add bulk load phase transitions (Triggered→Running in startMoveKeys,
  Running→Complete in finishMoveKeys) that were previously only in startMoveShards
- Pass dataMoveId through rawStartMovement and rawFinishMovement

BulkLoadUtil (BulkLoadUtil.cpp/.h):
- New getBulkLoadTaskStateByRange() function that reads bulkLoadTaskKeys directly
  using krmGetRanges, with the same retry/version logic as the old function

Test (BulkLoading.toml):
- Changed shard_encode_location_metadata from true to false to exercise the new
  decoupled path