Snowflake does not enforce uniqueness of PRIMARY KEY by default

[radeusgd]

Like in the title - for 'Standard' tables, Snowflake does not enforce uniqueness of the primary key.

One can make it enforce it by creating a HYBRID table.

Some of our Upload_Spec tests rely on the PRIMARY KEY uniqueness. We should try adapting them to run the tests on HYBRID tables to actually correctly test this.

Also review if any other operations (like Lookup) do not rely in some ways on the uniqueness.