Editing style for a row isn't well defined

[g-Off]

We are basing the editing style on the presence of rowActions/leading/trailing config. This isn't right but is needed for the moment for backwards compatibility. https://github.com/Shopify/FunctionalTableData/commit/795046694d85f5370e798c77813aefce7fccd954

We should instead provide a canDelete or deleteAction type mechanism that this delegate method would utilize. Should also look into that 3rd insert state that I can't remember the purpose of anymore