title: Wrong collation in Migrations after updating to Pomelo 5.0.3
body: <p>We have updated from Pomelo 5.0.0-alpha.2 to 5.0.3. We are facing some issues now when creating new migrations with foreign keys:</p>
  <pre><code>migrationBuilder.AddColumn&lt;Guid&gt;(
                  name: &quot;UserId&quot;,
                  table: &quot;MyTable&quot;,
                  type: &quot;char(36)&quot;,
                  nullable: true,
                  collation: &quot;ascii_general_ci&quot;);
  </code></pre>
  <p>This is our entity configuration:</p>
  <pre><code>public class MyTableEntityConfiguration : 
  {
      public override void Configure(EntityTypeBuilder&lt;MyTableEntity&gt; builder)
      {
          base.Configure(builder);
  
          builder.HasOne(x=&gt; x.User)
              .WithMany()
              .HasForeignKey(x=&gt; x.UserId)
              .HasPrincipalKey(user =&gt; user.Id);
      }
  }
  </code></pre>
  <p>And our entity:</p>
  <pre><code>public class MyTable
  {
          public Guid? UserId { get; set; }
          public UserEntity User { get; set; }
  }
  </code></pre>
  <p>A wrong collation (&quot;ascii_general_ci&quot;) is now being added causing the migration to fail when it's executed:</p>
  <p>Failed executing DbCommand (5ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
  ALTER TABLE <code>MyTable</code> ADD CONSTRAINT <code>FK_MyTable_Users_UserId</code> FOREIGN KEY (<code>UserId</code>) REFERENCES <code>Users</code> (<code>Id</code>) ON DELETE RESTRICT;</p>
  <p>The only solution we have found so far is to remove the &quot;collation: &quot;ascii_general_ci&quot; in the migration. Is there a better solution to not add the collation (or only the correct one) in the migrations automatically? Our database is setup to use the &quot;Default charset&quot;.</p>