## What changes were proposed in this pull request?
The ColumnPruning rule tries adding an extra Project if an input node produces fields more than needed, but as a post-processing step, it needs to remove the lower Project in the form of "Project - Filter - Project" otherwise it would conflict with PushPredicatesThroughProject and would thus cause a infinite optimization loop. The current post-processing method is defined as:
```
private def removeProjectBeforeFilter(plan: LogicalPlan): LogicalPlan = plan transform {
case p1 Project(_, f Filter(_, p2 Project(_, child)))
if p2.outputSet.subsetOf(child.outputSet) =>
p1.copy(child = f.copy(child = child))
}
```
This method works well when there is only one Filter but would not if there's two or more Filters. In this case, there is a deterministic filter and a non-deterministic filter so they stay as separate filter nodes and cannot be combined together.
An simplified illustration of the optimization process that forms the infinite loop is shown below (F1 stands for the 1st filter, F2 for the 2nd filter, P for project, S for scan of relation, PredicatePushDown as abbrev. of PushPredicatesThroughProject):
```
F1 - F2 - P - S
PredicatePushDown => F1 - P - F2 - S
ColumnPruning => F1 - P - F2 - P - S
=> F1 - P - F2 - S (Project removed)
PredicatePushDown => P - F1 - F2 - S
ColumnPruning => P - F1 - P - F2 - S
=> P - F1 - P - F2 - P - S
=> P - F1 - F2 - P - S (only one Project removed)
RemoveRedundantProject => F1 - F2 - P - S (goes back to the loop start)
```
So the problem is the ColumnPruning rule adds a Project under a Filter (and fails to remove it in the end), and that new Project triggers PushPredicateThroughProject. Once the filters have been push through the Project, a new Project will be added by the ColumnPruning rule and this goes on and on.
The fix should be when adding Projects, the rule applies top-down, but later when removing extra Projects, the process should go bottom-up to ensure all extra Projects can be matched.
## How was this patch tested?
Added a optimization rule test in ColumnPruningSuite; and a end-to-end test in SQLQuerySuite.
Author: maryannxue <maryannxue@apache.org>
Closes#21674 from maryannxue/spark-24696.
797971ed42