bugfix/wiz_control_associations: fix for issue#34

[cvirtucio]

Description

This is a bug fix for issue#34. A couple of things were happening:

Diffs were appearing even for the same control ID values in the same order

I am not entirely sure yet why this is the case. Supposedly terraform will not present a diff if the values and their order are the same. I think terraform is presenting a diff
because of some internal state that shows the resource data is getting modified at all. So we gate the call to d.Set("control_ids") on the presence of actual
differences in the cleanControls and the resource data's control IDs.

ForceNew was forcing destruction of association

I am not entirely sure why ForceNew is even necessary since the association isn't a real resource, and just calls the UpdateControl mutation on the wiz GraphQL API. And that update certainly happens in-place, rather than requiring a complete re-creation.