Generalize Components Coupled to Chain Package

[aaronbuchwald]

Decouple components that are unnecessarily tied to the chain package because they depend on either the block or transaction types. We should remove the pattern of using a resolutions.go and dependencies.go file to pass around mega objects and switch to passing in the required parameters to each type we need to construct.

Replace the dependencies.go file with passing in the minimal required functionality for the package and use a generic type for blocks/transactions where necessary, so that the code can be re-used with alternative block/transaction types:

• State Sync (Move statesync to separate package #1759)
• Tx Network Gossip (General tx gossip handler #1764)
• Builder (Generalize builder #1767)
• APIs