ENGCOM-1504: [Backport] 'Add Block Names to Hints' config setting to represent what it actually does #15105

 - Merge Pull Request #15105 from sergiy-v/magento2:feature/2.1-block-class-type-config-label
 - Merged commits:
   1. 841b322

Author: magento-engcom-team

app/code/Magento/Backend/etc/adminhtml/system.xml

@@ -116,7 +116,7 @@
                     <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                 </field>
                 <field id="template_hints_blocks" translate="label" type="select" sortOrder="21" showInDefault="1" showInWebsite="1" showInStore="1">
-                    <label>Add Block Names to Hints</label>
+                    <label>Add Block Class Type to Hints</label>
                     <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                 </field>
             </group>

app/code/Magento/Backend/i18n/en_US.csv

@@ -324,7 +324,7 @@ Developer,Developer
 Debug,Debug
 "Enabled Template Path Hints for Storefront","Enabled Template Path Hints for Storefront"
 "Enabled Template Path Hints for Admin","Enabled Template Path Hints for Admin"
-"Add Block Names to Hints","Add Block Names to Hints"
+"Add Block Class Type to Hints","Add Block Class Type to Hints"
 "Template Settings","Template Settings"
 "Allow Symlinks","Allow Symlinks"
 "Warning! Enabling this feature is not recommended on production environments because it represents a potential security risk.","Warning! Enabling this feature is not recommended on production environments because it represents a potential security risk."