Improve functionality of sample detectors

[ohltyler]

Sample detectors were originally released when the plugin only had single entity, real-time detectors. With the addition of high-cardinality and historical detectors, the plugin should offer corresponding sample offerings of those to help users get familiar with the new features. This will require making the sample data more complex and stretch farther in the past.

A few options:

1. Keep existing scenarios (HTTP responses, eCommerce, host health) and let user choose within those modules on what they want to create - (1) single-entity real-time, (2) high-cardinality real-time, (3) historical, or some combination of those.
2. Provide separate scenarios to highlight the common use cases for the different types of detectors. Maybe only offer 1 example of each, and customize the data accordingly.