Fix/multitenancy middleware scope

[mheidari988]

Summary

• Resolve multitenancy middleware scoped services per request to avoid root-provider resolution failures (e.g., during NSwag startup), and update/add tests to cover the new behavior.

Testing

• dotnet test
• Other (add details):

Checklist

• Includes docs/changelog updates if user-facing
• Adds/updates tests
• Keeps public API surface minimal and backward compatible (or documents breaking change)
• PR scoped to a single concern/module where possible

Notes

• Breaking changes? The public TenantResolutionMiddleware constructor signature changed (now only RequestDelegate), which breaks direct instantiation; standard usage via UseCleanArchitectureMultitenancy() is unaffected.
• Related issues/links: