Remove any reference to Provide commercial infrastructure

[kthomas]

As part of diligence prior to the official kickoff of PRVD OASIS, we need to ensure there are no references to any of Provide's commercial infrastructure (including naming of environment variables in the form of PROVIDE_). Any such traces need to be converted into a proper interface.

NChain may have a reference to api.providepayments.com in the environment and utils package that need to be converted into a proper interface.