Ensure cost directives are picked up when not explicitly imported

[tninesling]

With the recent composition changes, importing @cost results in a supergraph schema with the cost specification import at the top. The @cost directive itself is not explicitly imported, as it's expected to be available based on being the default export from the cost specification. In contrast, uses of @listSize to translate to an explicit import in the supergraph.

Old SDL link

@link(
    url: "https://specs.apollo.dev/cost/v0.1"
    import: ["@cost", "@listSize"]
)

New SDL link

@link(url: "https://specs.apollo.dev/cost/v0.1", import: ["@listSize"])

This exposed the brittle initial implementation of cost directive handling, which built up a map of directive name aliases from import statements. The core change made to address this issue is to remove the directive name map and replace it with calls to SpecDefinition::directive_name_in_schema, which is equivalent to the change we made on the composition side.

To avoid passing these names around during directive parsing, I have moved the directive parsing code into the CostSpecDefinition. This means the demand control plugin does not need to be concerned with the directives names in each schema.

---

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[router-perf]

CI performance tests

• connectors-const - Connectors stress test that runs with a constant number of users
• const - Basic stress test that runs with a constant number of users
• demand-control-instrumented - A copy of the step test, but with demand control monitoring and metrics enabled
• demand-control-uninstrumented - A copy of the step test, but with demand control monitoring enabled
• enhanced-signature - Enhanced signature enabled
• events - Stress test for events with a lot of users and deduplication ENABLED
• events_big_cap_high_rate - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity
• events_big_cap_high_rate_callback - Stress test for events with a lot of users, deduplication enabled and high rate event with a big queue capacity using callback mode
• events_callback - Stress test for events with a lot of users and deduplication ENABLED in callback mode
• events_without_dedup - Stress test for events with a lot of users and deduplication DISABLED
• events_without_dedup_callback - Stress test for events with a lot of users and deduplication DISABLED using callback mode
• extended-reference-mode - Extended reference mode enabled
• large-request - Stress test with a 1 MB request payload
• no-tracing - Basic stress test, no tracing
• reload - Reload test over a long period of time at a constant rate of users
• step-jemalloc-tuning - Clone of the basic stress test for jemalloc tuning
• step-local-metrics - Field stats that are generated from the router rather than FTV1
• step-with-prometheus - A copy of the step test with the Prometheus metrics exporter enabled
• step - Basic stress test that steps up the number of users over time
• xlarge-request - Stress test with 10 MB request payload
• xxlarge-request - Stress test with 100 MB request payload

[lrlna]

I like that we are moving this logic to apollo-federation crate. Makes this a lot cleaner! I have a couple of small suggestion and a question, but neither is blocking.

And overall question though, is this getting an update on the JS side, and do we need to bump router-bridge still? If so, we should get that in today, since the rc goes on wednesday.

[tninesling]

And overall question though, is this getting an update on the JS side, and do we need to bump router-bridge still? If so, we should get that in today, since the rc goes on wednesday.

This change was made on the JS side in apollographql/federation#3136, which was release in federation 2.9.3, so it's already in the current bridge.