### What changes were proposed in this pull request?
This PR changes `AttributeSet` and `ExpressionSet` to maintain the insertion order of the elements. More specifically, we:
- change the underlying data structure of `AttributeSet` from `HashSet` to `LinkedHashSet` to maintain the insertion order.
- `ExpressionSet` already uses a list to keep track of the expressions, however, since it is extending Scala's immutable.Set class, operations such as map and flatMap are delegated to the immutable.Set itself. This means that the result of these operations is not an instance of ExpressionSet anymore, rather it's a implementation picked up by the parent class. We also remove this inheritance from `immutable.Set `and implement the needed methods directly. ExpressionSet has a very specific semantics and it does not make sense to extend `immutable.Set` anyway.
- change the `PlanStabilitySuite` to not sort the attributes, to be able to catch changes in the order of expressions in different runs.
### Why are the changes needed?
Expressions identity is based on the `ExprId` which is an auto-incremented number. This means that the same query can yield a query plan with different expression ids in different runs. `AttributeSet` and `ExpressionSet` internally use a `HashSet` as the underlying data structure, and therefore cannot guarantee the a fixed order of operations in different runs. This can be problematic in cases we like to check for plan changes in different runs.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Passes `PlanStabilitySuite` after regenerating the golden files.
Closes#29598 from dbaliafroozeh/FixOrderOfExpressions.
Authored-by: Ali Afroozeh <ali.afroozeh@databricks.com>
Signed-off-by: herman <herman@databricks.com>
0a6043f683