NewExplorerHashHandler creates a handler to handle GET requests to /explorer/hash/:hash.

RegisterExplorerHTTPHandlers registers the (tfchain-specific) handlers for all Explorer HTTP endpoints.

ExplorerHashERC20Info contains all ERC20 related info as part of an UnlockHash-typed ExplorerHashGET request.

ExplorerHashGET wraps around the default rivine ExplorerHashGET type, as to add the optional ERC20 address to it, for UnlockHash requests, which have an ERC20 address attached to it.