fix(federation/composition): fixed context spec's argument type computation

[duckki]

Updated ContextSpecDefinition::field_argument_specification to retrieve the referenced type name using the provided link argument to the get_type closure. Also, refactored to share the argument name constant from the federation spec module.

Note: The ContextSpecDefinition is used for both federation spec and context spec. The link argument provides the correct context to the closure.

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[github-actions[bot]]

@duckki, please consider creating a changeset entry in /.changesets/. These instructions describe the process and tooling.

[apollo-librarian[bot]]

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* (developer-tools)/apollo-mcp-server/(latest)/command-reference.mdx
* (developer-tools)/apollo-mcp-server/(latest)/guides/index.mdx

Build ID: fee40f36261dc6bcb1a2e84b

URL: https://www.apollographql.com/docs/deploy-preview/fee40f36261dc6bcb1a2e84b

[duckki]

@tninesling Welcome back!