Consider disabling adding implicit group bys in LogicalPlanBuilder by default

[alamb]

          I lean towards having the default behaviour be `false` for this, even if it's a breaking change, because it makes the builder less surprising IMO. Specifically, when invoking the builder for an aggregate with a specific set of grouping expressions, my expectation is that it should produce an aggregate with those specific grouping expressions. If I wanted additional grouping expressions, I would have included them.

There's definitely room and value for optimizations like what is going on here, but I think those need to be opt-in to avoid situation like this were the plan builder tries to be smart along one specific axis and inadvertently shoots you in the foot in another. In the past, I think we've leaned towards having the builder be as straightforward as possible and then handling optimizations in the optimizer.

Originally posted by @vbarua in #14860 (comment)

[alamb]

FYI @akurmustafa / @mustafasrepo -- as I think you wrote the original version of this code

[alamb]

Actually i misread the diff, it seems like #14860 actually changes the default to false, which I think is a good change.