### What changes were proposed in this pull request?
Spark can't push down scan predicate condition of **Or**:
Such as if I have a table `default.test`, it's partition col is `dt`,
If we use query :
```
select * from default.test
where dt=20190625 or (dt = 20190626 and id in (1,2,3) )
```
In this case, Spark will resolve **Or** condition as one expression, and since this expr has reference of "id", then it can't been push down.
Base on pr https://github.com/apache/spark/pull/28733, In my PR , for SQL like
`select * from default.test`
`where dt = 20190626 or (dt = 20190627 and xxx="a") `
For this condition `dt = 20190626 or (dt = 20190627 and xxx="a" )`, it will been converted to CNF
```
(dt = 20190626 or dt = 20190627) and (dt = 20190626 or xxx = "a" )
```
then condition `dt = 20190626 or dt = 20190627` will be push down when partition pruning
### Why are the changes needed?
Optimize partition pruning
### Does this PR introduce _any_ user-facing change?
NO
### How was this patch tested?
Added UT
Closes#28805 from AngersZhuuuu/cnf-for-partition-pruning.
Lead-authored-by: angerszhu <angers.zhu@gmail.com>
Co-authored-by: AngersZhuuuu <angers.zhu@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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