Add support for query_insights_config in primary and read instances

[45413]

Currently the module does not support configuration for query insights, so any manual enabling of query insights on a primary or read instance results in a terraform plan that wants to revert those settings.

example except from plan with a primary instance that has had query insights enabled

~ resource "google_alloydb_instance" "primary" {
    ...
      - query_insights_config {
          - query_plans_per_minute  = 5 -> null
          - query_string_length     = 1024 -> null
          - record_application_tags = false -> null
          - record_client_address   = false -> null
        }
    ...
    }