[FLINK-36093][transform] fix preTransformoperator wrongly filters columns when multiple transform

[MOBIN-F]

Currently, such transform rule could not work:

transform:
projection: 'A' as result
filter: tag >= 0
projection: score as result
filter: tag < 0

Here, score column will be filtered out in PreTransform stage, since it wasn't referenced in the first transform rule. As a result, the following transform rule will fail since score does not exist in PostTransform operator.