Enable Pomelo MySQL project and add EF Core Relational

framework/Volo.Abp.slnx

@@ -81,7 +81,7 @@
     <Project Path="src/Volo.Abp.DistributedLocking.Dapr/Volo.Abp.DistributedLocking.Dapr.csproj" />
     <Project Path="src/Volo.Abp.DistributedLocking/Volo.Abp.DistributedLocking.csproj" />
     <Project Path="src/Volo.Abp.Emailing/Volo.Abp.Emailing.csproj" />
-    <!-- <Project Path="src/Volo.Abp.EntityFrameworkCore.MySQL.Pomelo/Volo.Abp.EntityFrameworkCore.MySQL.Pomelo.csproj" /> -->
+    <Project Path="src/Volo.Abp.EntityFrameworkCore.MySQL.Pomelo/Volo.Abp.EntityFrameworkCore.MySQL.Pomelo.csproj" />
     <Project Path="src/Volo.Abp.EntityFrameworkCore.MySQL/Volo.Abp.EntityFrameworkCore.MySQL.csproj" />
     <Project Path="src/Volo.Abp.EntityFrameworkCore.Oracle.Devart/Volo.Abp.EntityFrameworkCore.Oracle.Devart.csproj" />
     <Project Path="src/Volo.Abp.EntityFrameworkCore.Oracle/Volo.Abp.EntityFrameworkCore.Oracle.csproj" />

framework/src/Volo.Abp.EntityFrameworkCore.MySQL.Pomelo/Volo.Abp.EntityFrameworkCore.MySQL.Pomelo.csproj

@@ -22,6 +22,7 @@
 
     <ItemGroup>
         <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" />
+        <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" />
     </ItemGroup>
 
 </Project>