Minor: Use execution error in ScalarValue::iter_to_array for incorrect usage

[jayzhan211]

Which issue does this PR close?

Closes #.
Part of #11992

Since ScalarValue::iter_to_array is a widely used directly function, I think it makes sense to return execution error instead of internal error.

Rationale for this change

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[alamb]

I personally think the internal error makes more sense but I don't have a problem changing this

I think the idea about returning internal error was that if these errors get hit, then it signals some bug in the datafusion code -- it is not something you can likely fix by updating your query

[jayzhan211]

I personally think the internal error makes more sense but I don't have a problem changing this
I think the idea about returning internal error was that if these errors get hit, then it signals some bug in the datafusion code

I think the problem is typically for a function that is both used directly from down stream project and internally. We return internal error even it is used incorrectly from down stream project, which is actually not the bug from datafusion. #11992 is one of the case. I'm still struggle with what error should I used AGAIN 😆

[jayzhan211]

Thanks @alamb