Add ability to enable/disable features in the Fleet UI

[noahtalerman]

Goal

As a Fleet admin/operator, I would like the ability to enable or disable features via the Fleet UI so that I don't have to configure these features at runtime.

Use case

Limit the potential personal info gathered by fleet, in this case, the user email address

Fleet now gathers the logged-in user email from the chrome profiles depending on a companies stance of using a corporate device for personal use this may inadvertently expose user information that they may not want to gather from user systems.

• [ ] Provide a toggle to opt to gather this information or not?

How?

• [ ] Move the admin config away from feature flags into the database so they don't have to be configured at runtime.
• [ ] Create an admin UI to enable/disable & configure features whilst the service is running.
• [ ] Allow the config to be defined in YAML / Applied via fleetctl

[noahtalerman]

The Toggle opt-in or out functionality is more than likely is a larger FR

I agree with this. However, it's possible to take iterative steps by introducing the toggle opt-on or out functionality for 1 or 2 features to start.

@gavinelder, when you thought about this toggle improvement, which feature(s) did you want to disable? (other than the Chrome email).

Allow the config to be defined in YAML / Applied via Fleetctl?

Currently, the software inventory (enable_software_inventory), vuln detection (also enable_software_inventory), and (enable_host_users) system users can all be defined in the config yaml document.

It makes sense to introduce these^ toggles in the UI and add additional toggles to the UI and config yaml document.