Add the GraphQL endpoint support

[andrii-bodnar]

Crowdin API client doesn't support the GraphQL endpoint yet. We should add support for it in this API client.

References:

• GraphQL API documentation
• JS API client implementation example

[imprvhub]

Hi @andrii-bodnar! i would like to contribute to this issue, can you assign me? Thanks!

[imprvhub]

@andrii-bodnar, I see two possible approaches for implementing GraphQL support:

1. Adding it directly to the CrowdinClient class (for example in client.py and requester.py)
2. Creating a new module under api_resources following the project's pattern (for example:
   crowdin_api/api_resources/graphql/
   ├── _ _ init _ _.py
   ├── resource.py
   ├── types.py
   ├── tests/
   └── test_graphql_resources.py)

Which approach would you prefer? Thanks!

[andrii-bodnar]

@imprvhub I like the first approach. Also, it's something similar to what we have in JS API Client

[imprvhub]

@andrii-bodnar It's done! Let me know if you have any suggestions for corrections.