Step 1.2 - Add ApplicationContextTracer to Graphql Schema

• DRAFT: Full Context MR
• Step 1.1 - Create graphql_known_operations from webpack plugin
• Step 1.2 - Add ApplicationContextTracer to Graphql Schema
• Step 2 - Add LoggerTracer to Graphql Schema
• Step 3 - Add MetricsTracer to Graphql Schema

What does this MR do and why?

This MR sets up the initial GraphQL tracer which writes to the Gitlab::ApplicationContext based on the specific query. This application context is read from when writing various logs, so it's very helpful to give this operation specific information (not just GraphqlController#execute).

This is also used by the upcoming LoggerTracer.

Screenshots or screen recordings

Not really relevant yet. Locally, I'm not noticing any logs which use caller_id while executing a GraphQL query.

Description	Screenshot
caller_id for request log remains unchanged. This is good because a single request can handle multiple queries.

But! This will come up soon with the upcoming LoggerTracer and MetricsTracer

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #331697 (closed)