Add pre back into protected environments

[Cruikshanks]

https://eaflood.atlassian.net/browse/WATER-4351

The project comes with an inbuilt mechanism to configure routes to not be available in protected environments, for example, production.

You can see this in app/routes/data.routes.js. Both /data/seed and /data/tear-down are configured to be excludeFromProd.

How this works is during startup our app/plugins/router.plugin.js calls app/services/plugins/filter-routes.service.js which handles filtering out those routes that should not be added when running in a protected environment.

To be honest, excludeFromProd is a bad name because it could be any environment we add to this

function _protectedEnvironment (environment) {
  return ['prd'].includes(environment)
}

When this was first implemented pre was included so we could confirm routes were not available before shipping to production. However, in Create endpoint to generate fake data we took it out so we could get this fake data generator to work. It needed to be in pre because it generated data based on real bill runs.

Clearly, we weren't on the ball because we didn't even bother to update the comments which still exist

 * So, we use this service to ensure any endpoint that is still being worked on is not available when the API is
 * running in production. We also include pre-production in our protected environments so we can test and ensure
 * an endpoint does not get registered as part of our release testing and sign-off.

Since that time the fake data generator is no more and we need to be able to test again that routes (and therefore pages) are not accessible in production. Hence, we need to add pre back into our list of protected environments.

[Cruikshanks]

Just added @Beckyrose200 and @rvsiyad as reviewers as this is connected to their work so they need to know about it. Hence the description is 1000x larger than the change! 😬

[rvsiyad]