Add graphql query

[denisart]

1. Fix for datamodel-code-generator

From version 0.25.0 datamodel-code-generator can generation pydantic classes from some GraphQL schema

2. graphql-query -- Complete Domain Specific Language (DSL) for GraphQL query based on pydantic.

src: https://github.com/denisart/graphql-query in graphql.org: see clients in https://graphql.org/code/#python docs: https://denisart.github.io/graphql-query/

new feature: Can to use pydantic classes as data-model for generation a GraphQL query: https://denisart.github.io/graphql-query/from_data_model/