[Redshift Dv2] Handle svv_table_info permissions

[cynthiaxyin]

From Slack thread.

(paraphrased) V2 introduced a new "is your table empty" check, which relies on querying the svv_table_info view. we could modify that check to do some sort of select exists(...) query to avoid asking for more permissions, but presumably there’s a minor cost tradeoff there, especially wrt to upgrading.

Data point: beta user was OK with granting more permission to the Airbyte user (if we stick with this route, we should add this info to the docs)

[evantahler]

Grooming:

• Dv2 needs more permissions. This table is what we use to get the approx # rows in the table (how we can tell if the table exists w.o doing a read). This is equivalent to INFORMATION_SCHEMA (trading a potentially harder setup for faster syncs). We should:
  1. Add a read to CHECK command to make sure we can access. We should try a SELECT * FROM svv_table_info LIMIT 1 to check access.
  2. Add to docs that we need READ permission on this table.