test(api): add unit tests for requestDeduplicator module (closes #1192)

[rupesh-kumar-sah]

Overview

Closes #1192.

Adds comprehensive unit tests for in .

Test Coverage

• Constants and Exports: Verifies (30s), (100), and singleton instance.
• Concurrent Request Deduplication: Verifies multiple concurrent identical requests resolve to a single network call invocation.
• State Properties: Tests and properties tracking active in-flight calls and returning to 0 upon completion.
• Sequential Execution: Asserts that subsequent calls after settlement execute freshly.
• Key Differentiation: Confirms distinct requests are differentiated by HTTP method, endpoint path, and query params.
• Error Propagation: Ensures executor errors reject all waiting subscribers and purge the failed entry so future attempts can retry cleanly.
• Cancellation & Cleanup: Tests propagation, invocation, and LRU cache eviction when exceeding .

Verification

• Linted with ESLint and formatted with Prettier (0 errors, 0 warnings).