## What changes were proposed in this pull request?
When reordering joins EnsureRequirements only checks if all the join keys are present in the partitioning expression seq. This is problematic when the joins keys and and partitioning expressions both contain duplicates but not the same number of duplicates for each expression, e.g. `Seq(a, a, b)` vs `Seq(a, b, b)`. This fails with an index lookup failure in the `reorder` function.
This PR fixes this removing the equality checking logic from the `reorderJoinKeys` function, and by doing the multiset equality in the `reorder` function while building the reordered key sequences.
## How was this patch tested?
Added a unit test to the `PlannerSuite` and added an integration test to `JoinSuite`
Closes#25167 from hvanhovell/SPARK-27485.
Authored-by: herman <herman@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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