Minor schema cosmetic code fixes, more Attribute implementation from old pla, start of LDAP DN view/edit

app/Classes/LDAP/Attribute/ObjectClass.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace App\Classes\LDAP\Attribute;
+
+use App\Classes\LDAP\Attribute;
+
+/**
+ * Represents an attribute whose values are jpeg pictures
+ */
+final class ObjectClass extends Attribute
+{
+	public function __toString(): string
+	{
+		return $this->values->sort()->join('<br>');
+	}
+}