Fix the GraphQL logs for multiplex queries

What does this MR do?

The previous implementation was using the operationName parameter received by the controller but this parameter is nil for multiplex queries as there are multiple queries to execute in one request. With this change, we are now relying on an analyzer to get the operation names for all types of queries.

This will change the graphql attribute of the JSON object from an object to an array of objects but the objects in the array will have the same keys and by default, all the keys can hold an array of things on ElasticSearch so this shouldn't break the auto-indexing feature.

Does this MR meet the acceptance criteria?

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