[PLUGIN][AttachmentCollections] Restore functionality

Some minor corrections

components/Collection/Entity/Collection.php

@@ -0,0 +1,67 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Component\Collection\Entity;
+
+use App\Core\Entity;
+use function mb_substr;
+
+class Collection extends Entity
+{
+    // These tags are meant to be literally included and will be populated with the appropriate fields, setters and getters by `bin/generate_entity_fields`
+    // {{{ Autocode
+    // @codeCoverageIgnoreStart
+    private int $id;
+    private string $name;
+    private int $actor_id;
+
+    public function setId(int $id): self
+    {
+        $this->id = $id;
+        return $this;
+    }
+
+    public function getId(): int
+    {
+        return $this->id;
+    }
+
+    public function setName(string $name): self
+    {
+        $this->name = mb_substr($name, 0, 255);
+        return $this;
+    }
+
+    public function getName(): string
+    {
+        return $this->name;
+    }
+
+    public function setActorId(int $actor_id): self
+    {
+        $this->actor_id = $actor_id;
+        return $this;
+    }
+
+    public function getActorId(): int
+    {
+        return $this->actor_id;
+    }
+
+    // @codeCoverageIgnoreEnd
+    // }}} Autocode
+
+    public static function schemaDef()
+    {
+        return [
+            'name'   => 'collection',
+            'fields' => [
+                'id'       => ['type' => 'serial', 'not null' => true, 'description' => 'unique identifier'],
+                'name'     => ['type' => 'varchar', 'length' => 255, 'not null' => true, 'description' => 'collection\'s name'],
+                'actor_id' => ['type' => 'int', 'foreign key' => true, 'target' => 'Actor.id', 'multiplicity' => 'one to many', 'not null' => true, 'description' => 'foreign key to actor table'],
+            ],
+            'primary key' => ['id'],
+        ];
+    }
+}