feat: support configuring database settings

[sweatybridge]

What kind of change does this PR introduce?

feature

What is the new behavior?

resource "supabase_settings" "production" {
  project_ref = "mayuaycdtijbctgqbycg"

  database = jsonencode({
    statement_timeout = "10s"
  })
}

The database settings is special because the default values are automatically adjusted when you upgrade compute size. For this reason, the supabase api only returns the overrides instead of the full settings currently.

Additional context

Add any other context or screenshots.