[fix]: Include TenantId and UserId in GlobalExceptionHandler Logs

Description

This PR enhances the GlobalExceptionHandler to improve observability in multi-tenant environments. It ensures that every exception logged includes the relevant tenant_id and user_id context.

Key Changes:

• DI Scope Conflict Resolution: Refactored GlobalExceptionHandler to resolve IMultiTenantContextAccessor and ICurrentUser dynamically from HttpContext.RequestServices. This prevents System.InvalidOperationException when a Singleton handler attempts to consume Scoped services.
• Serilog LogContext Enrichment: Automatically pushes tenant_id and user_id to the Serilog LogContext when an exception occurs.
• Enhanced Log Messages: Updated the error log template to explicitly show the Tenant and User involved (e.g., Exception at /api/endpoint (Tenant: root, User: Anonymous) - Detail...).

Related Issues

• Complements tenancy isolation improvements.
• Resolves local issue Bump Microsoft.EntityFrameworkCore.Design from 5.0.8 to 5.0.9 #17.

Verification

• Unit Testing: Added GlobalExceptionHandlerTests in Generic.Tests using NSubstitute to verify context extraction and log enrichment.
• Build: Success with zero errors.
• Manual Check: Verified that the application starts correctly and the builder.Build() AggregateException is resolved.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)