MC-18332: Remove MySQL Search Engine

- adding annotations

Author: cpartica

app/code/Magento/AdvancedSearch/Model/Client/ClientResolver.php

@@ -5,8 +5,9 @@
  */
 namespace Magento\AdvancedSearch\Model\Client;
 
-use \Magento\Framework\ObjectManagerInterface;
+use Magento\Framework\ObjectManagerInterface;
 use Magento\Framework\Search\EngineResolverInterface;
+use Magento\Framework\App\Config\ScopeConfigInterface;
 
 /**
  * @api
@@ -46,7 +47,7 @@ class ClientResolver
     private $clientOptionsPool;
 
     /**
-     * @var EngineResolver
+     * @var EngineResolverInterface
      */
     private $engineResolver;
 

app/code/Magento/CatalogSearch/Model/Indexer/Scope/State.php

@@ -18,6 +18,9 @@
  * The 'use_temporary_table' state is an opposite for 'use_main_table'
  *   which means that default indexer table should be left unchanged during indexation
  *   and temporary table should be used instead.
+ *
+ * @deprecated
+ * @see \Magento\Elasticsearch
  */
 class State
 {

app/code/Magento/CatalogSearch/Model/ResourceModel/EngineInterface.php

@@ -15,6 +15,7 @@ interface EngineInterface
 {
     /**
      * @deprecated
+     * @see \Magento\Framework\Search\EngineResolverInterface
      */
     const FIELD_PREFIX = 'attr_';
 

app/code/Magento/Elasticsearch/Model/ResourceModel/Engine.php

@@ -61,7 +61,7 @@ public function allowAdvancedIndex()
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
      */
     public function processAttributeValue($attribute, $value)
     {
@@ -74,7 +74,7 @@ public function processAttributeValue($attribute, $value)
      *
      * @param array $index
      * @param string $separator
-     * @return string
+     * @return array
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
     public function prepareEntityIndex($index, $separator = ' ')
@@ -83,7 +83,7 @@ public function prepareEntityIndex($index, $separator = ' ')
     }
 
     /**
-     * {@inheritdoc}
+     * @inheritdoc
      */
     public function isAvailable()
     {