Improvements to GraphQL

[scottyeager]

Currently we write something like this:

graphql.nodes(['nodeID'], power={'state_eq': 'Down'}, updatedAt_gt=int(1234.567))

Some aspects could be nicer:

• We have a mix of quoted strings and unquoted keyword arg names
• There's also a mix of keyword args and passing dicts for nested queries
• It's possible to pass invalid names in some places with no error given, for example power={'state': 'Down'}
• We must cast to the correct data type explicitly

Ideally we could:

from grid3.names import *
graphql.nodes([nodeID], power(state=Down), updatedAt_gt=1234.5678)

By implementing:

• names contains variables with the same name as all possible strings used in gql queries (nodeID = 'nodeID', etc), as well as functions with the name of any nested parameters (power) that just return a simple data structure with their own name and any keyword args
• Make _eq the default operator when none is specified (also check and reject invalid parameter names)
• Automatically convert to the correct data type for the input (can derive this from the schema?)