Provide a better experience for using resolved fiels in (third party) tools

[hobofan]

Right now we have two main ways that a set of field dependencies are usable:

• Via the CLI via the plow protege command (downside: format specific to Protege)
• Via the libraries (downside: not usable via the CLI)

To be better usable across a wide variety of tools it would be good to make the output of the dependency resolution and retrieval process accessible in an easy to digest way, which any other tools could integrate with.

E.g. we could have a plow install command, which places (or symlinks) the retrieved fields into a directory inside the workspace (e.g. plow_fields as an analogue to node_modules), together with metadata that would make it easy to load those fields.