Add resource provider allowlist

[bgins]

General Description

On some networks, the solver may choose to limit the resource providers that are allow to make resource offers. For example, our upcoming beta program will only allow a select group of resource providers until we open the network.

Please note that our plan for Lilypad mainnnet is an open network where any resource provider may connect and offer their compute resources.

Which system(s) or functionality does this affect

This change affects the solver and resource provider.

Describe the changes, and how this affects/ interacts with each system.

This solver will implement and use the allowlist. The solver can enable or disable the allowlist. When the allowlist is enabled, resource providers must be in the list to post their resource offer to the solver.