Enable exception-less execution for 404/1002, 403, and 400 status codes

[Copilot]

Enables exception-less execution for session-not-found (404/1002), forbidden (403), and bad-request (400) responses. These scenarios now return status codes instead of throwing exceptions, eliminating exception handling overhead during retries.

Changes

• RequestMessage.cs: Set UseStatusCodeFor4041002, UseStatusCodeFor403, and UseStatusCodeForBadRequest to true by default
• ExceptionLessTests.cs: Added FirstChanceException monitoring to validate zero exceptions thrown for these scenarios in both Gateway and Direct modes

Context

Session consistency with stale LSN tokens produces 404/1002 responses during normal operation. Exception-based handling incurs unnecessary overhead:

// Before: Exception thrown and caught during retry
// After: Status code checked, no exception overhead
ResponseMessage response = await container.ReadItemStreamAsync(id, pk, 
    new ItemRequestOptions { SessionToken = staleToken });
// response.StatusCode == 404, SubStatusCode == 1002

Impact

• Performance: Eliminates exception stack unwinding for common retry scenarios
• Compatibility: Stream APIs unaffected (already status-code based). Typed APIs catching these specific exceptions will see behavior change.

Reference: https://msdata.visualstudio.com/CosmosDB/_git/CosmosDB?path=/Product/SDK/.net/Microsoft.Azure.Cosmos.Friends/tests/ExceptionLessTests.cs

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