title: Is column a discriminator?
body: <p>If a user does something like this inside <code>OnModelCreating</code>:</p>
  <pre class="lang-cs prettyprint-override"><code>modelBuilder.Entity&lt;MyBaseEntity&gt;.HasDiscriminiator(x =&gt; x.EntityType)
  </code></pre>
  <p>Outside <code>OnModelCreating</code>, is it possible to either get the full list of discriminator columns or check if a particular column was configured as discriminator?</p>
  <p>Thanks.</p>