Consider rewriting update resolvers in javascript

[NoisyFlowers]

The resolvers that handle delete mutations are all written in javascript. This javascript generates cypher code and uses the Neo4j javascript driver. The advantages of this approach are:

• ability to refactor common cypher generation code into utility routines
• ability to have transactions that span multiple cypher statements
• more flexibility in error handling

The existing update resolvers are working, but we should consider rewriting them to be similar to the delete resolvers.

[aazaff]

I believe we decided to do this across the board.

[NoisyFlowers]

This is finished. The only resolvers left in schema.graphql are create and update for CharacterInstance. There are unique bits there that do not lend themselves to cypher-generation in javascript.