HoodieTableState is write-only except latestCommitTimestamp; collapse it into a plain parameter

[voonhous]

Problem

After #19458, latestCommitTimestamp is the only field of HoodieTableState (hudi-spark-common, HoodieBaseRelation.scala) that anything still reads -- two .withLatestCommitTime(tableState.latestCommitTimestamp.orNull) calls in HoodieMergeOnReadRDDV2.compute.

The other seven fields (tablePath, recordKeyField, orderingFields, usesVirtualKeys, metadataConfig, recordMergeImplClasses, recordMergeStrategyId) are write-only: populated once in HoodieBaseRelation.tableState and never read. The reads died in #17457 (FileGroupReader migration for all Spark datasource reads), #13544 and #12981; usesVirtualKeys appears never to have been read at all. The whole object (including a full HoodieMetadataConfig with its Properties) is a non-transient field of HoodieMergeOnReadRDDV2, so it is serialized into every MOR task for the sake of one Option[String].

Proposal

Delete HoodieTableState entirely and pass latestCommitTimestamp directly to HoodieMergeOnReadRDDV2:

• HoodieBaseRelation: drop the HoodieTableState case class and the tableState lazy val (the recordMergerImpls local and the fileIndex.getMetadataConfig call there become dead too; the relation-level recordKeyField / orderingFields lazy vals must stay -- they are still read via mandatoryFieldsForMerging and the incremental relation traits)
• HoodieMergeOnReadRDDV2: replace the tableState: HoodieTableState constructor parameter with latestCommitTimestamp: Option[String]
• Update the three composeRDD call sites (MergeOnReadSnapshotRelation, MergeOnReadIncrementalRelationV1/V2)

Flagged by @wombatu-kun while reviewing #19458 ("worth dropping the other seven by the same criterion, or noting that they are deliberately kept - follow-up, not a blocker"); kept out of that PR to avoid growing an already-reviewed diff.