Fix papi.d.ts not showing some JSDoc comments

[tjcouch-sil]

Fix imports in papi so you can actually see comments and such instead of individually setting types on things like dataProvider.

This is important because, at the current moment, extensions see very few comments when they are using intellisense on papi. For example, you can see a function signature but no JSDoc comments on papi.dataProvider.get. This will severely impact extension developers' ability to write extensions easily:

Note you can make jsdocs inherit from parent classes or interfaces and such with /** @inheritDoc **/ apparently! Not sure how relevant that is to this particular issue.

[tjcouch-sil]

Split off the bullet "Remove internal-only dependencies that are not actually used anywhere on the papi (ex: node/services/node-file-system.service)" into #175