Java Doublets Adapter via GraphQL client

[konard]

500 RUB reward can be claimed by anyone who completes this task.

This adapter should provide standard Doublets CRUD operations API in the native to Java code style (the most commonly used one).
The libraries' architecture should take in account the ability to swap GraphQL with a native library that will be shipped later (when we finish translation to C++).
The GraphQL client layer should be usable separately as well as native to Java's API.

There should be 3 packages for Maven/Ivy:

1. Platform.Data.Doublets.Native (DLL api wrapped in Java only)
2. Platform.Data.Doublets.Gql.Client (GraphQL client to doublets only)
3. Platform.Data.Doublets.Client (Abstract API for both Platform.Data.Doublets.Native and Platform.Data.Doublets.Gql.Client)