Query does not provide a operation name as a property in the request body causing some server configurations to reject the request

The [Apollo implementation](https://github.com/ardatan/graphql-tools/blob/64cbe00c702529bca8a6277bbafc5f20bcb5d8e9/packages/loaders/apollo-engine/src/index.ts#L24) for fetching the schema does not provide an operation name in the boy of the request like so.
```json
{
"query":"SCHEMA_QUERY",
"variables":{
"id":"options.graph",
"tag":"options.variant"
},
"operationName":"GetSchemaByTag"
}
```
It is common practice to reject queries without an operation names for a variety of reasons. Apollo Server/Federation implementation only exposes the operationName defined in the request body for plugins not in the query causing any teams enabled or created a plugin to reject queries without OperationNames to reject the introspection query.

Start in packages/loaders/apollo-engine/src/index.ts at the linked schema-fetching implementation and compare its request body with the example in the issue. Confirm the request includes the operationName value GetSchemaByTag, then check the loader's existing validation or test coverage if available and verify the request is accepted by configurations that require operation names.

Written by the indexing model from the issue text.