(SDL / Execution) Handle "input" type for mutation

[tsunammis]

Hello,

As specified in the specification, we have to use the type input type for complex inputs in mutation, instead of using the regular Object type which can contain interface, union or arguments.

What we should do

input RecipeInput {
  id: Int
  name: String
  cookingTime: Int
}

type Mutation {
  updateRecipe(input: RecipeInput): Recipe
}

instead of

type RecipeInput {
  id: Int
  name: String
  cookingTime: Int
}

type Mutation {
  updateRecipe(input: RecipeInput): Recipe
}

Request sample

mutation {
  updateRecipe(input: {
        id: 1, 
        name: "The best Tartiflette by Eric Guelpa", 
        cookingTime: 12
  }) {
    id
    name
    cookingTime
  }
}

• Tartiflette version: 0.4.0
• Python version: 3.7.1
• Executed in docker: No
• Is a regression from a previous versions? No