These keys are for pre-built Entities and apps. The keys you mentioned are for the Cortana app that you can create on http://luis.ai:

I'm not sure if there's a way to retrieve all the intents as the link to the documentation seems to be broken, but this site seems to have a list of the intents as well (behind a paywall).

Update: new docs mention not to use these keys:
We recommend that you use the prebuilt domains, instead of the Cortana prebuilt app. For example, instead of builtin.intent.calendar.create_calendar_entry, use Calendar.Add from the Calendar prebuilt domain. The prebuilt domains provide these advantages:
They provide packages of prebuilt and pretrained intents and entities that are designed to work well with each other. You can integrate a prebuilt domain directly into your app. For example, if you're building a fitness tracker, you can add the Fitness domain and have an entire set of intents and entities for tracking fitness activities, including intents for tracking weight and meal planning, remaining time or distance, and saving fitness activity notes.
The prebuilt domain intents are customizable. For example, if you want to provide reviews of hotels, you can train and customize the Places.GetReviews intent from the Places domain to recognize requests for hotel reviews.
The prebuilt domains are extensible. For example, if you want to use the Places prebuilt domain in a bot that searches for restaurants, and need an intent for getting the type of cuisine, you can build and train a Places.GetCuisine intent.
Credit to Ryan for the link.