Backend: Create Deed External Adapter

[Robert-H-Leonard]

In order to make deed data available on-chain we need an external adapter (this is the mechanism our chainlink node uses to get data off-chain). The external adpater will be a single function, that takes a single street address, the chainlink node can call. The external adapter should do 3 things:

1. Parse the incoming request for the street address -> call the function created in this issue to get deed data.

2. Upload deed data to ipfs (along with other metadata such as timestamps, datasource name, etc.) and get an ipfs hash

3. Return the ipfs hash to the chainlink node

External Adapter docs: https://docs.chain.link/docs/external-adapters/
Some example nodejs external adapters: https://github.com/smartcontractkit/external-adapters-js/tree/develop/packages/sources

Notes

Some examples to see how it works: https://github.com/smartcontractkit/external-adapters-js/tree/develop/packages/sources