Option to require admin approval for location portal

[danirabbit]

Imagining a situation where we have an administered user like a child or in a kiosk situation, we might not want non-admin users to be allowed to approve location services requests.

We should probably have a setting so that we can require admin permission if the admin wants to set things up that way

[steakscience]

I think it would make sense to add the same locking/unlocking feature from the Users settings to the locations setting