Move services to fog-core

These services were missed in the initial work.
Remove duplicate requires from services

Following work on reorganising the requires, there was an inconsistent
approach to where service wrappers are required. (Fog::Compute...)

Since they should be standardised and shared across providers (although
they really aren't yet) they have been moved to `fog-core` gem.

Each provider has their own `lib/fog/{provider}/core` files that is
required by each of their services. These files should all require
`fog/core` which already required most or these.

So this removes the extra cases to concentrate them in core.
Merge pull request #2670 from fog/remove_remaining_services

[core] Remove remaining services