Add Sql method to DbRepository and EFCore.Relational refs

Added a Sql method to DbRepository for executing raw SQL queries
via FromSqlRaw. Included Microsoft.EntityFrameworkCore.Relational
package references for all target frameworks to support this
functionality. Cleaned up unused using directives.

DigitalData.Core.Infrastructure/DbRepository.cs

@@ -1,11 +1,9 @@
 using AutoMapper;
 using DigitalData.Core.Abstraction.Application.Repository;
-using DigitalData.Core.Abstractions.Interfaces;
 using DigitalData.Core.Infrastructure.Factory;
 using Microsoft.EntityFrameworkCore;
 using System.Linq.Expressions;
-using Microsoft.Extensions.DependencyInjection;
-
+using Microsoft.EntityFrameworkCore.Query;
 #if NETFRAMEWORK
 using System.Collections.Generic;
 using System;
@@ -44,6 +42,11 @@ namespace DigitalData.Core.Infrastructure
             Mapper = mapper;
         }
 
+        public IQueryable<TEntity> Sql([NotParameterized] string sql, params object[] parameters)
+        {
+            return Entities.FromSqlRaw(sql, parameters);
+        }
+
         #region Create
         public virtual async Task<TEntity> CreateAsync(TEntity entity, CancellationToken cancel = default)
         {