Renamed config setting to represent what it actually does

This config name is notoriously misleading as it does not show the block name at all, instead it shows the block class type. Worse still there is a question about this in the Magento2 certification exam which is utterly confusing due to the poor naming of the config setting.

Author: chris-pook

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

@@ -120,7 +120,7 @@
                     <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>