Fix unmonitored devices issues

[benarmston]

Allows fixing some issues with unmonitored devices.

The "you have unmonitored devices" popup still appears. When it does, the user can click on the provided link from where they will be able to configure the MIA to monitor the entire data centre. Once done:

• The popup will no longer appear.
• Devices will not list themselves in the unmonitored group.
• The CT appliances group will not be empty.