display exact json what is being signed for ``keybase track XXX``

It seems that there is no possibility to view the exact data which I sign when I track, and decide to push the tracking information onto the server. Do I actually sign the pgp key, or all identity proofs? Or what else?

Start with the `keybase track XXX` entry point and determine which data is signed before tracking information is sent to the server. Done means the user can view the exact JSON and distinguish whether it contains the PGP key, identity proofs, or other tracking data.

Written by the indexing model from the issue text.