feat: Support custom warehouse sizes

[waffleshop]

Summary

Supports custom warehouse sizes as Snowflake customers are now able to submit support tickets to raise their limit beyond 10.

Test Plan

# Previous max size
resource "snowflake_warehouse" "old" {
  name              = "test_old"
  comment           = "foo"
  warehouse_size    = "small"
  max_cluster_count = 10
}

# Unlimited max size
# This should only work on accounts where the soft limit has been increased with a support case.
resource "snowflake_warehouse" "new" {
  name              = "test_new"
  comment           = "foo"
  warehouse_size    = "small"
  max_cluster_count = 20
}

References

• Nothing to link to, unfortunately. Informed by our Snowflake representative that this is now a soft limit.

[sfc-gh-swinkler]

/ok-to-test sha= 3be94c3

[github-actions]

Integration tests failure for

[alldoami]

/ok-to-test sha=3be94c3

[github-actions]

Integration tests success for 3be94c3