feat: update Tracer.java for hub

[DavePearce]

The aim here is to resolve the issue with the column RELATIVE_BLOCK_NUMBER which is not currently being written into the lt trace files.

[DavePearce]

Currently in hub/fragment/common/CommonFragment.java we have this:

public Trace trace(Trace trace) {
    final CallFrame frame = commonFragmentValues.callFrame;
    final TransactionProcessingMetadata tx = commonFragmentValues.txMetadata;
    final boolean isExec = commonFragmentValues.hubProcessingPhase == TX_EXEC;
    return trace
        .absoluteTransactionNumber(tx.getAbsoluteTransactionNumber())
        .batchNumber(tx.getRelativeBlockNumber())
        ...

After regenerating the Trace.java the batchNumber has disappeared. However, I do see .relativeBlockNumber() which looks like a sensible replacement?