[DPC-5169] add lookbook to test env

[lukey-luke]

🎫 Ticket

DPC-5169

🛠 Changes

• update routes to include lookbook routes for when "ENV" == "test"

ℹ️ Context

• working with content + design in sprint 1.3, I discovered that some application states are difficult to reproduce, like the error message for Login.gov being unavailable
  • For folks to review these types of messages, lookbook is an easier option than having developers force certain application states
  • By adding lookbook to test, all content review can be done on test between logged in views requiring AO invite as well as navigating to https://test.dpc.cms.gov/portal/lookbook

🧪 Validation

Manually tested this in test environment

[ashley-weaver]

works for me!

[MEspositoE14s]

👍