Added Create and Delete tag actions

module/Core/src/Repository/TagRepository.php

@@ -0,0 +1,29 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Repository;
+
+use Doctrine\ORM\EntityRepository;
+use Shlinkio\Shlink\Core\Entity\Tag;
+
+class TagRepository extends EntityRepository implements TagRepositoryInterface
+{
+    /**
+     * Delete the tags identified by provided names
+     *
+     * @param array $names
+     * @return int The number of affected entries
+     */
+    public function deleteByName(array $names)
+    {
+        if (empty($names)) {
+            return 0;
+        }
+
+        $qb = $this->getEntityManager()->createQueryBuilder();
+        $qb->delete(Tag::class, 't')
+           ->where($qb->expr()->in('t.name', $names));
+
+        return $qb->getQuery()->execute();
+    }
+}

module/Core/src/Repository/TagRepositoryInterface.php

@@ -0,0 +1,17 @@
+<?php
+declare(strict_types=1);
+
+namespace Shlinkio\Shlink\Core\Repository;
+
+use Doctrine\Common\Persistence\ObjectRepository;
+
+interface TagRepositoryInterface extends ObjectRepository
+{
+    /**
+     * Delete the tags identified by provided names
+     *
+     * @param array $names
+     * @return int The number of affected entries
+     */
+    public function deleteByName(array $names);
+}