Reconsider arguments passed to get_endpoint_args_for_item_schema() #1135

In aba6bef, @joehoyle added $add_required_flag = true argument to get_endpoint_args_for_item_schema(). This feels a little bit unglamorous.

We discussed a bit and came up with two options:

• get_endpoint_args_for_item_schema( array( ‘add_required_flag’ => true ) )
• get_create_endpoint_args() and get_update_endpoint_args()

The latter feels cleaner.