Suport "rename" annotate directive in schema

[fetsorn]

Add "rename" feature to the annotate directive in GraphQL type.

MarketData2(helloWorld=md1.hello_world)

type MarketData1 {
   hello-world: String! @annotate(rename="helloWorld", exclude=true)
}
 
type MarketData2 {
  helloWorld: String!
}

md1: MarketData1
md2 = md1.transform()

[Niraj-Kamdar]

I'd expand this in the ability to add schema transformations: Here are some common transformations:

1. rename field while transforming
   • field/type aliases for the types that can't be represented in programming langs
   • rename the field to the desired name
2. exclude selected fields
3. only include selected fields
4. transform array of pair into a map and vice-versa
5. Can in future support many such transformations if needed to