Handle large outputs in receipts as CID'ed

[zeeshanlakhani]

Summary

As discussed in #450, we need a way to handle large outputs. Instead of the receipt returning the output, that output could be turned into a CID, stored in Homestar, and then IPFS by default, or allow the option for elsewhere.

Components

• Threshold for the size of a receipt output
• If >= Threshold, the output becomes a CID and possibly includes a URL in the metadata to where to retrieve it from (defaults = IPFS).
• If < Threshold, the output is directly inlined (like today)