Multi-agent furniture moving/lifting support

[Lucaweihs]

Problem

We would like to support the multi-agent FurnMove and FurnLift tasks we have introduced in prior work.

Solution

We will need to implement the Task, TaskSampler, and models from https://github.com/allenai/cordial-sync.

Dependencies

This should only be undertaken after multi-agent support is in (#109).

[Lucaweihs]

@unnat @Lucaweihs will provide any support needed for this as we are the authors of the above repo.