Multi-Network Support in snarkOS

[damons]

This epic is create functionality in snarkOS to support multiple concurrent networks running (potentially) under one snarkOS node. Also, it could mean simply the ability to specify which network to run using command-line arguments, etc. Please add all issues here to describe all dependencies for this epic.

[Protryon]

This is contributed to significantly by ongoing blocked storage refactors. See https://github.com/AleoHQ/snarkVM/issues/247