Add sessionless param to graphql context

What does this MR do?

To implement #232841 (closed), we need to distinguish between requests coming directly from GraphQL (and a bearer token) and those where the user comes from the session. Why? Because we want to track the usage of the snippet editor by unique users.

The snippet editor uses GraphQL and we need to identify those requests coming from there. These requests will retrieve the user from the session.

In this MR we add a helper attribute in the GraphQL controller that help us identify whether the user was retrieved from the session or not.

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Refs #232841 (closed)