public Builder addColumn(Types.NestedField sourceColumn) {
      pkFields.add(new PrimaryKeyField(sourceColumn.name()));
      return this;
    }
parse primary key spec from table properties

@param schema - base store table schema
@param keyDescription - key description of {#{@link #description}}
@return primary key spec.
amoro-format-iceberg/src/main/java/org/apache/amoro/table/PrimaryKeySpec.java