refactor: rename batch-related variables and functions for consistency and clarity

cmd/go_migrate/process.go

@@ -44,7 +44,7 @@ func processMigrationJob(
 	jobCtx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	partitions, err := partitionGeneratorMssql(jobCtx, sourceDb, job.SourceTable, job.RowsPerBatch)
+	partitions, err := partitionGeneratorMssql(jobCtx, sourceDb, job.SourceTable, job.RowsPerPartition)
 	if err != nil {
 		log.Error("Unexpected error calculating batch ranges: ", err)
 	}
@@ -81,7 +81,7 @@ func processMigrationJob(
 				jobCtx,
 				job.SourceTable,
 				sourceColTypes,
-				job.ChunkSize,
+				job.BatchSize,
 				chPartitions,
 				chBatchesRaw,
 				chExtractorErrors,