Redesign Cryptomoji App

[delventhalz]

The Cryptomoji App should be redesigned to remove most of the extra noise that distracts students from the actual Sawtooth implementation, as well as front-loading the more typical blockchain behavior (trading).

This redesign should also include re-ordering tests so that services methods are implemented as they are needed, not front-loaded where they are implemented without any context.

Finally this redesign must address #82 by generating an ID for moji (and perhaps collections) that is independent of state address.

Rough new design and implementation order:

• Create Collection: Creates empy collection (no moji); encoding; ID generation
• Front End MVP: Login/signup with private keys; encoding; signing; collection txn, address, and request
• Spawn Moji: Adds moji to a collection; FE should display moji; moji txn, address, and request
• Trade Moji: Create/accept/reject Offer (should address TP: Cut offers down to MVP #85); delete state; FE trade UI; offer txn, address, and request
• Breed Moji (Extra Credit): Select sire; breed moji; family tree added to moji entity; FE breeding UI; sire txn, address, and request
• Additional Offer Validation (Extra Credit): Handle the many complex offer fail states (such as TP: Track offer/response involvement on each moji #57, TP: Prevent users from adding sire in offers #77)
• Counter-Offers (Extra Credit, possible): Adds additional functionality to Offers, allowing counter-offers, similar to original offer functionality.