Enable users to enable/disable connectors through an admin UI

[shadyvb]

There may be some default connectors that may not be desired, rather than having to write an mu-plugin to disable the connector, it would be easier to provide this ability as an option in the UI.

[frankiejarrett]

I really like this idea, and I'd like to think about adding a new Settings tab just for connectors. However, before we do that I think there would need to justify it by having other settings available for connectors too not just for activating/deactivating them.

[shadyvb]

@fjarrett I do think this is a quite important feature for big sites/network, if the administrator does not care about actions on posts or media or so, which i believe is very possible, this would be a big step towards a really flexible monitoring tool without adding a bulk of actions i'm not really interested in.

Another step deep into the same goal, though not important as much, would be to manage actions of each connector.

[shadyvb]

Closing as PR was merged.