add ability to (non-intrusively) ask users about their needs

[diosmosis]

To better understand how our users use Matomo, what they need from the tool, what's missing without waiting for them to provide feedback, it would be good to have the ability to directly (and non-intrusively) ask them.

To simplify the implementation, these questions should not be dynamic, that is, they should not come from an external service. Instead, they can be hard coded in the release.

This may be something we only enable once. Or we may add some generic questions and never change them again.

Refs #1056