RFC - ownership grants

[ryanking]

I started looking into #304 and it got me thinking- maybe we should move "ownership" grants to be part fo the resources being owned.

Here's is my line of thinking, please correct me if I am wrong about any of this, I know terraform far better than snowflake.

1. There can only be one owner for a given object
2. The other variant of grant ownership, grant ownership on all tables in schema mydb.public to role analyst copy current grants (example from preceding link) does not work well with terraform because it is non deterministic.

So I am thinking that we remove the ability to grant ownership from the snowflake_*_grant resources and instead add an owner attribute to each resource which can be owned. We can do it in two passes, one where we support both methods, with the old one being marked as deprecated and a second pass where we remove the old method.

Feedback please.