Refactor configuration

[tilacog]

Adapt all startup parameters to support multiple protocol networks.

Options changes:

• ethereum —> network-providers
  • format: list of network_identifier:network_provider_url
  • still support the old argument name, ethereum, mark it as deprecated and move towards removing it
• network-subgraph-urls
  • format: list of network_identifier:network_subgraph_url
• epoch-subgraph-urls
  • format: list of network_identifier:epoch_subgraph_url
• note: network_identifier can support both numeric CAIP2 ids OR their string aliases
• Validations:
  • lists provided to the three protocol network options must have same length
  • user must provide all three above values for each network_identifier
  • if no network_identifier provided, fall back to older behavior, can only use one network in that case.

[tilacog]

Closing in favor of #668