Send custom fields into template

[MAILPOET-2453]

lib/Entities/CustomFieldEntity.php

@@ -0,0 +1,60 @@
+<?php
+
+namespace MailPoet\Entities;
+
+use DateTimeInterface;
+use MailPoet\Doctrine\EntityTraits\AutoincrementedIdTrait;
+use MailPoet\Doctrine\EntityTraits\CreatedAtTrait;
+use MailPoet\Doctrine\EntityTraits\UpdatedAtTrait;
+use MailPoetVendor\Doctrine\ORM\Mapping as ORM;
+use MailPoetVendor\Symfony\Component\Validator\Constraints as Assert;
+
+/**
+ * @ORM\Entity()
+ * @ORM\Table(name="custom_fields")
+ */
+class CustomFieldEntity {
+  use AutoincrementedIdTrait;
+  use CreatedAtTrait;
+  use UpdatedAtTrait;
+
+  /**
+   * @ORM\Column(type="string", nullable=false, unique=true)
+   * @var string
+   */
+  private $name;
+
+  /**
+   * @ORM\Column(type="string", nullable=false)
+   * @var string
+   */
+  private $type;
+
+  /**
+   * @ORM\Column(type="json_or_serialized")
+   * @Assert\NotBlank()
+   * @var array
+   */
+  private $params;
+
+  /**
+   * @return string
+   */
+  public function getName() {
+    return $this->name;
+  }
+
+  /**
+   * @return string
+   */
+  public function getType() {
+    return $this->type;
+  }
+
+  /**
+   * @return array
+   */
+  public function getParams() {
+    return $this->params;
+  }
+}