Integration Tests - AWS PrivateLink Connection

[bobbyiliev]

Add an integration test for AWS PrivateLink Connection as per the discussion here: #37

[bobbyiliev]

Added PL tests for some of the connection resources like Postgres, MySQL and Kafka connections:

terraform-provider-materialize/integration/connection.tf

Lines 115 to 122 in 235671e

	aws_privatelink {
	privatelink_connection {
	name = "privatelink_conn"
	database_name = "materialize"
	schema_name = "public"
	}
	privatelink_connection_port = 9092
	}

Currently creating a PL connection works, but dropping it crashes the container. So for the time being I'm only creating a PL connection using the init container and then using that connection to test other resources.

Last step here would be to just be able to create and drop PL connections so we could add acceptance and integration tests.