refactor: update partition handling to use Range struct for better clarity and consistency

internal/app/etl/extractors/mssql.go

@@ -107,13 +107,13 @@ func (mssqlEx *MssqlExtractor) ProcessPartition(
 	indexPrimaryKey int,
 	chBatchesOut chan<- models.Batch,
 ) (int, error) {
-	query := buildExtractQueryMssql(tableInfo, columns, partition.ShouldUseRange, partition.IsLowerLimitInclusive)
+	query := buildExtractQueryMssql(tableInfo, columns, partition.HasRange, partition.Range.IsMinInclusive)
 
 	var queryArgs []any
-	if partition.ShouldUseRange {
+	if partition.HasRange {
 		queryArgs = append(queryArgs,
-			sql.Named("min", partition.LowerLimit),
-			sql.Named("max", partition.UpperLimit),
+			sql.Named("min", partition.Range.Min),
+			sql.Named("max", partition.Range.Max),
 		)
 	}