Implement new retrieval market Client API functions from latest go-fil-markets

[shannonwells]

Description

go-fil-markets PR #190 modifies the return values of its Client API function, GetOrCreatePaymentChannel, and adds two API calls to the retrieval market API which allow creating or adding funds to a payment channel to be non-blocking waiting for messages to be on chain.

1. Modify GetOrCreatePaymentChannel:

   • if payment channel does not exist, call create without waiting for the message to be mined, then return address.Undef, message CID, error/nil
   • If payment channel exists, send requested funds to the payment channel without waiting for the message to be mined, then return the payment channel address, message CID, error/nil

2. Implement WaitForPaymentChannelCreation

    // WaitForPaymentChannelCreation waits for a message on chain that a
    // payment channel has been created
    WaitForPaymentChannelCreation(messageCID cid.Cid) (address.Address, error)
   

   If the message is mined within the timeout, return the new payment channel unique address.
   This function also receives a message CID to wait for with a timeout after which it will error.

3. Implement WaitForPaymentChannelAddFunds

    // WaitForPaymentChannelAddFunds waits for a message on chain that funds have
    // been sent to a payment channel
    WaitForPaymentChannelAddFunds(messageCID cid.Cid) error
   

   This function receives a message CID to wait for with a timeout, after which it returns error, otherwise nil

This function will return

Acceptance criteria

Above implemented as subscribed, with unit tests and integration test