[BB2] BlenderBot FiD agent that uses Wizard of Internet's original retrieved docs

[mojtaba-komeili]

Patch description

BlenderBot 2 FiD model with gold retrieved documents (documents that were shown to the crowdsourcing agents during data collection). It uses the ObservationEchoRetriever retriever for reading the observed messages from the content of the message from the Wizard of Internet teacher.

Test

Running a few steps of training

parlai train -t wizard_of_internet \
--model projects.blenderbot2.agents.blenderbot2:BlenderBot2WizIntGoldDocRetrieverFiDAgent \
--batchsize 4 --dict-file zoo:blender/reddit_3B/model.dict -tr 32

Note

• There was a nit change on the wizard of internet task for consistency.
• Training with this agent doesn't require using search engine.
• This knowledge retriever part of this agent only works with Wizard of Internet dataset, or any dataset that has similar messages (the content under knowledge component keys).