Refactor user entities and repositories, update seeders

Standardized property naming in user-related entities to use 'Id' suffix (e.g., UserAccountId). Moved and updated repository interfaces and implementations to the DataAccessLayer.Repositories namespace. Refactored DBSeed seeders to use repository classes and improved structure. Updated .gitignore and project references

DBSeed/ISeeder.cs

@@ -1,6 +1,9 @@
 using Microsoft.Data.SqlClient;
 
-interface ISeeder
+namespace DBSeed
 {
-    Task SeedAsync(SqlConnection connection);
+    internal interface ISeeder
+    {
+        Task SeedAsync(SqlConnection connection);
+    }
 }