--------------------
This PR adds a MaxTokensLimiter extension which limits the number of tokens in a GraphQL document.
Usage example:
python
import strawberry
from strawberry.extensions import MaxTokensLimiter
schema = strawberry.Schema(
Query,
extensions=[
MaxTokensLimiter(max_token_count=1000),
],
)
Contributed by [reka](https://github.com/reka) via [PR #2729](https://github.com/strawberry-graphql/strawberry/pull/2729/)