fix: initialize resolveReferences object and add type info to nodeId resolution

[mgagliardo91]

This PR fixes two minor bugs with the current federation plugin and adds tests to validate bi-directional federation with postgraphile.

The two main bugs were:

1. resolveReferences on the build object for the plugin was not initialized and would throw an error when doing a lookup for in the entities resolver
2. Type information was not being added to entities that were resolved by nodeId link

While updating the PR, I added some docker support for simplifying the test suite so that individuals would not have to have postgres installed on their machines. This can be removed from this PR, if desired.

The test updates should now check bi-directional federation:

• Extending a postgraphile entity (existing)
• Federating to a postgraphile entity by nodeId
• Federating to a postgraphile entity by primary key (in this case id)

[mgagliardo91]

@jarvisuser90 thanks for owning the more current fork of https://github.com/graphile/federation . I was able to get it working with the latest release of Apollo Federation with a few minor changes. Let me know if there is any specific contribution requests you would prefer to see.

[mgagliardo91]

@jarvisuser90 are you still active in this repo?