Remove unneeded code + tests
Always include initial request in response
Resolved object gets passed to response
Import load promise only needs request and document
Don't clone the request

- we aren't passing it into the Fcommand so it can only be changed by
  extension code
Simplify the response+cleanup logic

- since the promise chain propagates the initial object, augmented with
  context-specific data, then() calls can just pass each object along
  as-is