feat: adding secure views for snowflake

[benfdking]

Related to #3070

NOTE I know I need to revert a number of unnecessary format changes.

A few thoughts:

• [ ] I don't think this is tested enough because I haven't run anything against Snowflake
• [ ] I am not certain about the way I create the views, it's a bit ugly
• [ ] More generally, I am slightly nervous about the approach of just adding properties to the root model configuration that are specific to individual engines, as it feels like a way to get way too many confusing configuration points